AREAS FOR WHICH STATISTICS ARE PRESENTED

Regions, divisions, and States.-The geographic groupings of States by regions and divisions as shown in table 1 are the standard groupings used by the Bureau of the Census. Under this arrangement, the United States is first divided into four regions. The regions are divided, in turn, into a total of nine geographic divisions, each of which is composed of a specific group of contiguous States. (See map, p. xII.)

Standard metropolitan statistical areas. For many types of analysis, the entire area in and around a city, in which the activities form an integrated economic and social system, needs to be considered as a unit. Prior to the 1950 Censuses of Popu lation and Housing, areas of this type had been defined in different ways for different purposes and by various agencies. Leading examples were the metropolitan districts of the 1940 Census of Housing, the industrial areas of the Census of Manufactures, and the labor market areas of the Bureau of Employment Security. To permit all Federal statistical agencies to utilize the same areas for the publication of general-purpose statistics, the Bureau of the Budget has established "standard metropolitan statistical areas" (SMSA's). Every city of 50,000 inhabitants or more according to the 1960 Census of Population is included in an SMSA.

The definitions and titles of standard metropolitan statistical areas are established by the Bureau of the Budget with the advice of the Federal Committee on Standard Metropolitan Statistical Areas. This Committee is composed of representatives of the major statistical agencies of the Federal Government. The criteria used by the Bureau of the Budget in establishing the SMSA's are presented below. (See the Bureau of the Budget publication, Standard Metropolitan Statistical Areas, U.S. Government Printing Office, Washington 25, D.C., 1961.)

The definition of an individual SMSA involves two considerations: First, a city or cities of specified population to constitute the central city and to identify the county in which it is located as the central county; and second, economic and social relationships with contiguous counties which are metropolitan in character, so that the periphery of the specific metropolitan area may be determined.' SMSA's may cross State lines.

Population criteria.-The criteria for population relate to a city or cities of specified size according to the 1960 Census of Population.

1. Each standard metropolitan statistical area must include at least:

a. One city with 50,000 inhabitants or more, or

b. Two cities having contiguous boundaries and constituting, for general economic and social purposes, a single com

1 Central cities are those appearing in the standard metropolitan statistical area title. A contiguous" county either adjoins the county or counties containing the largest city in the area, or adjoins an intermediate county integrated with the central county. There is no limit to the number of tiers of outlying metropolitan counties so long as all other criteria are met.

munity with a combined population of at least 50,000, the smaller of which must have a population of at least 15,000.

2. If each of two or more adjacent counties has a city of 50,000 inhabitants or more (or twin cities under 1b) and the cities are within 20 miles of each other (city limits to city limits), they are to be included in the same area unless there is definite evidence that the two cities are not economically and socially integrated.

Criteria of metropolitan character.-The criteria of metropolitan character relate primarily to the attributes of the contiguous county as a place of work or as a home for a concentration of nonagricultural workers.

3. At least 75 percent of the labor force of the county must be in the nonagricultural labor force.2

4. In addition to criterion 3, the county must meet at least one of the following conditions:

a. It must have 50 percent or more of its population living in contiguous minor civil divisions with a density of at least 150 persons per square mile, in an unbroken chain of minor civil divisions with such density radiating from a central city in the area.

b. The number of nonagricultural workers employed in the county must equal at least 10 percent of the number of nonagricultural workers employed in the county containing the largest city in the area, or the county must be the place of employment of 10,000 nonagricultural workers.

c. The nonagricultural labor force living in the county must equal at least 10 percent of the number in the nonagricultural labor force living in the county containing the largest city in the area, or the county must be the place of residence of a nonagricultural labor force of 10,000.

5. In New England, the city and town are administratively more important than the county, and data are compiled locally for such minor civil divisions. Here, towns and cities are the units used in defining standard metropolitan statistical areas. In New England, because smaller units are used and more restricted areas result, a population density criterion of at least 100 persons per square mile is used as the measure of metropolitan character.

Criteria of integration.-The criteria of integration relate primarily to the extent of economic and social communication between the outlying counties and central county.

6. A county is regarded as integrated with the county or counties containing the central cities of the area if either of the following criteria is met:

a. Fifteen percent of the workers living in the county work in the county or counties containing central cities of the area,

or

b. Twenty-five percent of those working in the county live in the county or counties containing central cities of the area. Only where data for criteria 6a and 6b are not conclusive are other related types of information used as necessary. This information includes such items as average telephone calls per subscriber per month from the county to the county containing

2 Nonagricultural labor force is defined as those employed in nonagricultural occupations, those experienced unemployed whose last occupation was a nonagricultural occupation, members of the Armed Forces, and new workers.

3 A contiguous minor civil division either adjoins a central city in a standard metropolitan statistical area or adjoins an intermediate minor civil division of qualifying population density. There is no limit to the number of tiers of contiguous minor civil divisions so long as the minimum density requirement is met in each tier.

XI

central cities of the area; percent of the population in the county located in the central city telephone exchange area; newspaper circulation reports prepared by the Audit Bureau of Circulation; analysis of charge accounts in retail stores of central cities to determine the extent of their use by residents of the contiguous county; delivery service practices of retail stores in central cities; official traffic counts; the extent of public transportation facilities in operation between central cities and communities in the contiguous county; and the extent to which local planning groups and other civic organizations operate jointly.

Criteria for titles. The criteria for titles relate primarily to the size and number of central cities.

7. The complete title of an SMSA identifies the central city or cities and the State or States in which the SMSA is located: a. The name of the standard metropolitan statistical area includes that of the largest city.

b. The addition of up to two city names may be made in the area title, on the basis and in the order of the following criteria:

(1) The additional city has at least 250,000 inhabitants. (2) The additional city has a population of one-third or more of that of the largest city and a minimum population of 25,000, except that both city names are used in those instances where cities qualify under criterion 1b. (A city which qualified as a secondary central city in 1950 but which did not qualify in 1960 has been temporarily retained as a central city.)

c. In addition to city names, the area titles will contain the name of the State or States in which the area is located. SMSA maps and definitions.—The location of SMSA's in the country as a whole is shown in the map on p. xIv; for identification and location of SMSA's in each State, see individual maps of States beginning on p. 619.

The exact composition of each SMSA is shown in Appendix D. Standard consolidated areas. In view of the special importance of the metropolitan complexes around New York and Chicago, the Nation's largest cities, several contiguous SMSA's and additional counties that do not appear to meet the formal integration criteria but do have strong interrelationships of other kinds have been combined into the New York-Northeastern New Jersey and Chicago-Northwestern Indiana Standard Consolidated Areas, respectively. The former is identical with the New York-Northeastern New Jersey SMA of 1950, and the latter corresponds roughly to the Chicago SMA of 1950 (two more counties having been added).

State economic areas.-State economic areas are relatively homogeneous subdivisions of States. They consist of single counties or groups of counties which have similar economic and social characteristics. The boundaries of these areas have been drawn in such a way that each State is subdivided into relatively few parts, with each part having certain significant characteristics which distinguishes it from adjoining areas.

The State economic areas have been designed for use in tabulating and publishing census data of various types and for other purposes. In this volume, these areas and their components are identified only by codes and not by specific listing.

The grouping of the counties or equivalent subdivisions of the United States into State economic areas is the product originally of a special study sponsored by the Bureau of the Census in cooperation with the Bureau of Agricultural Economics and several State and private agencies for the 1950 censuses. The 1960 set of SEA's represents a limited revision of the 1950 areas. This revision takes into account changes in the definitions of SMSA's.

For further discussion and materials on State economic areas and their uses, see Bureau of the Census, State Economic Areas, U.S. Government Printing Office, Washington, D.C., 1951.

The combination of counties into State economic areas has been made for the entire country, and in this process the larger standard metropolitan statistical areas (those in 1960 with a central city of 50,000 or more and a total population of 100,000 or more) have been recognized as metropolitan State economic areas. When a standard metropolitan statistical area is located in two or more States, each State part becomes a metropolitan State economic area. In New England this correspondence does not exist because State economic areas are composed of counties, whereas standard metropolitan statistical areas are composed of towns. Here a county with more than half its population in one or more standard metropolitan statistical areas is classified as a metropolitan State economic area if the county or combination of counties containing the standard metropolitan statistical area or areas has 100,000 inhabitants or more.

Counties. The primary divisions of the States are, in general, termed counties. In Louisiana, these divisions are known as parishes. Alaska is divided into 24 election districts, included here as the equivalents of counties. Some data for Alaska are not available by election districts but are available for its former 4 judicial divisions. In such cases data for the latter are shown. In some States, there are cities which are independent of any county organization and thus constitute primary divisions of their States, namely, Baltimore in Maryland, St. Louis in Missouri, and 32 cities in Virginia. The District of Columbia also is included here as the equivalent of a county, as are the 3 parts of Yellowstone National Park in Idaho, Montana, and Wyoming. In 1960, there were 3,072 counties and parishes in the United States and 62 county equivalents, making a total of 3,134 (excluding the 4 judicial divisions in Alaska). See Appendix B for further detail.

Between 1950 and 1960, the number of counties declined by three-Armstrong County, S. Dak., was annexed by Dewey County; Elizabeth City County, Va., was consolidated with Hampton city; and Warwick County, Va., was consolidated with Newport News city. During the same period, county equivalents in conterminous United States increased by five, as five cities in Virginia-Covington, Galax, Norton, South Boston, and Virginia Beach-became independent of county organization.

Urbanized areas.-Although the major objective of the Bureau of the Census in delineating urbanized areas was to provide a better separation of urban and rural population in the vicinity of the larger cities, individual urbanized areas have proved to be useful statistical areas. They correspond to areas called "conurbations" in some other countries. An urbanized area contains at least one city of 50,000 inhabitants or more in 1960,5 as well as the surrounding closely settled incorporated places and unincorporated areas that meet the criteria listed below. An urbanized area may be thought of as divided into the central city or cities, and the remainder of the area, known as the urban fringe. All persons residing in an urbanized area are included in the urban population.

For the 1960 Census, urbanized areas were delineated in terms of the census results rather than on the basis of information available prior to the census, as was done in 1950. A peripheral zone was drawn around each 1950 urbanized area and around cities that were presumably approaching a population of 50,000. Within the unincorporated parts of this zone small enumeration

There are a few urbanized areas where there are "twin central cities," neither of which has a population of 50,000 or more but that have a combined population of at least 50,000.

districts were established, usually including no more than 1 square mile of land area and no more than 75 housing units." Arrangements were made to include within the urbanized area those enumeration districts meeting specified criteria of population density as well as adjacent incorporated places. Since the urbanized area outside incorporated places was defined in terms of enumeration districts, the boundaries for the most part follow such features as roads, streets, railroads, streams, and other clearly defined lines which may be easily identified by census enumerators in the field and often do not conform to the boundaries of political units.

In addition to its central city or cities, an urbanized area also contains the following types of contiguous areas, which together constitute its urban fringe:

1. Incorporated places with 2,500 inhabitants or more.

2. Incorporated places with less than 2,500 inhabitants, provided each has a closely settled area of 100 housing units or

more.

3. Towns in the New England States, townships in New Jersey and Pennsylvania, and counties elsewhere which are classified as urban.

4. Enumeration districts in unincorporated territory with a population density of 1,000 inhabitants or more per square mile. (The areas of large nonresidential tracts devoted to such urban land uses as railroad yards, factories, and cemeteries were excluded in computing the population density of an enumeration district.)

5. Other enumeration districts in unincorporated territory with lower population density provided that they served one of the following purposes:

a. To eliminate enclaves,

b. To close indentations in the urbanized areas of 1 mile or less across the open end, and

c. To link outlying enumeration districts of qualifying density that were no more than 1% miles from the main body of the urbanized area.

Contiguous urbanized areas with central cities in the same standard metropolitan statistical area are combined. Urbanized areas with central cities in different standard metropolitan statistical areas are not combined, except that a single urbanized area was established in the New York-Northeastern New Jersey Standard Consolidated Area, and in the Chicago-Northwestern Indiana Standard Consolidated Area,

The boundaries of the urbanized areas for 1960 do not conform to those for 1950, partly because of actual changes in land use and density of settlement, and partly because of relatively minor changes in the rules used to define the boundaries. In general, however, the urbanized areas of 1950 and 1960 are based on essentially the same concept, and the figures for a given urbanized area may be used to measure the population growth of that area.

Cities. The designation "city," in general, refers to a political subdivision of a State within a defined area over which a municipal corporation has been established to provide general local government for a specific population concentration. "Cities" as used in this volume refers to those places which are incorporated as cities, boroughs, towns, and villages with the exception that towns are not recognized as incorporated places in the New England States, New York, and Wisconsin. The towns in these States are minor civil divisions similar to the townships in some States and are not necessarily thickly settled centers of population such as the cities, boroughs, towns, and villages in other States. In this volume, the cities for which data are included in table 6 are those having a population of 25,000 inhabitants or more as reported in the 1960 Census of Population. All cities included are incorporated.

An enumeration district (ED) is a small area assigned to an enumerator which must be canvassed and reported separately. In most cases, an ED contained approximately 250 housing units.

Unincorporated urban places. In advance of the enumeration for the 1960 Census of Population, the Bureau of the Census delineated the boundaries for densely settled population centers without corporate limits. This volume presents data only for such places having 25,000 inhabitants or more in 1960.

Urban places.-These places comprise all incorporated and unincorporated places having 2,500 inhabitants or more in 1960 and those towns, townships, and counties classified as urban in the 1960 Census of Population. For a definition of "urban," see text for Items 6-7 under the "Source Notes and Explanations" section.

A list of all urban places and their population appears in Appendix A-2.

OTHER AREAS

The Bureau of the Census also collects and compiles statistics for other geographic entities which are not represented in this volume. Some of these are described below.

Congressional districts.-Congressional district boundaries are determined by State legislatures. The Congressional Apportionment Act of 1842 required every State populous enough to be entitled to more than one Representative to be divided by the State legislature into districts "composed of contiguous territory," each returning one member. While the districting requirement was omitted in the Apportionment Act of 1850, an act of 1862 revived the provisions of the original law of 1842. The Apportionment Act of 1872 continued the requirement of "contiguous territory" and added a provision that districts should contain “as nearly as practicable an equal number of inhabitants." The apportionment law of 1901 added the words "compact territory" to the previous requirement.

The number of Members in the House of Representatives is fixed by the Congress at the time of each apportionment. Between 1912 and 1959, the number of Representatives remained constant at 435. In 1959 the number was increased temporarily to 437 as a result of the admission of Alaska and Hawaii to the Union, each receiving 1 Representative.

Central business districts and major retail centers.-The primary objective of delineating “central business districts" (CBD's) is to provide a basis for comparing changes in business activity in the central business district with those in the remainder of the metropolitan area or of the central city. The delineation was accomplished by the Bureau of the Census with the cooperation of the Census Tract Committees representing a variety of local interests.

There are no universally accepted rules for determining what a CBD area should comprise. Therefore the Census Bureau, instead of providing rigid specifications for defining the CBD, provided a general characterization only. The Bureau described it as an area of very high land valuation, an area characterized by a high concentration of retail businesses, offices, theaters, hotels, and "service" businesses, and an area of high traffic flow; and required that the CBD ordinarily should be defined to follow existing tract lines, i.e., to consist of one or more whole census tracts (see below).

CBD's have been delineated only in those cities of 100,000 inhabitants or more (according to the 1950 Census of Population or a subsequent special census prior to 1959) in which there was a local Census Tract Committee recommendation for such an area.

Major retail centers (MRC's) were defined by the Bureau of the Census as those concentrations of retail stores (located inside the standard metropolitan statistical areas in which the CBD cities are located but outside of the CBD's themselves) which include a major general merchandise store-usually a department store. MRC's include not only the planned suburban