The publications for the 1870 through the 1900 census reflected a continuing interest in the use of counties as geographic building blocks for regions, particularly those regions based on physiography, topography, drainage basins, or river systems. Over the period 1850 through 1900, the number of counties and statistically equivalent entities increased from 1,621 to 2,828; the 1900 layout of county areas and boundaries largely resembled the present pattern. For census purposes, counties were becoming a stable framework of geographic units; this development favored their use as building blocks for data tabulation and presentation. They also served the need for a smaller set of geographic units on which to base regional configurations.
The Census Office’s 1874 Statistical Atlas contained a discussion of the physical features of the country, prepared by Professor J. D. Whitney. The atlas had no accompanying statistical tables, but Whitney’s discussion of physiographic regions in the text became the basis for a presentation of data by regions based on physical features in the 1880 census report. Before the publication of the 1874 text in the statistical atlas, the 1850 and 1860 census mortality tables also made partial use of county groupings as summary areas.
Gannett continued this approach in the 1880, 1890, and 1900 census publications. The 1880 census report presents some summary data by 21 topographic regions, a practice continued in the publications of the 1890 census and, with minor modifications, the 1900 census as well. The population report for 1890 focused extensively on geographic distributions by natural regions. These included not only demographic statistics by topographic divisions, but also others: drainage basins, altitude, mean annual temperature, and rainfall. All 1890 census tables contained historical information from 1870 and 1880 recomputed or rearranged to conform to topographic regions and other areas shown in maps from the 1874 Statistical Atlas. The 1900 census publication continued these presentations.
A 1900 census report shows the 19 topographic divisions delineated for that census, and lists the number of counties and statistically equivalent entities in each division. Geographic arrangements of natural regions present a
