The population data used in the graphs comes from A U.S. Bureau of the Census Preliminary Reports - 1970 Census of Population series PC (p2) Washington D.C. August 1970
3.
B U.S. Bureau of the Census StatisticalAbstract of the United States 196889th edition Washington D.C.1968 pp 21-22
4.
C U.S. Bureau of the Census U.S. Census of Population 1960 vol 1 Characteristics of the Population part A Number of Inhabitants U.S. Government Printing Office Washington D.C. 1961 pp 1-66 1-67
5.
The data refers to population of the central city only, not the more commonly used Standard Metropolitan Statistical Area (SMSA). The cities chosen for the graphs were selected arbitrarily.
6.
The population of different cities is shown on different scales here for ease of comparison. Numerical equality between the model and any particular city should not be expected because the model is deliberately general and not representative of any one city. Land area, for example, varies dramatically between cities, and one would expect to find a larger population supported on a larger area. The purpose here is to display the similar modes of population growth over time in cities different in many other ways.
7.
Some urban land area data can be gleaned from the decennial population census, the source of the data for the cities used in this paper.
8.
A U.S. Bureau of the Census U.S. Census of Population: 1930, Metropolitan Districts Population and Area
9.
B U.S. Bureau of the Census U.S. Census of Population: 1950, United States Summary, Number of Inhabitants, Table 17
10.
C U.S. Bureau of the Census U.S. Census of Population: 1970, Supplementary Report, PC(S1)-26-August, 1972
