U.S. Census Office, Center of Population at Each Census, 1790 to 1890 (1898)

The mean center of the U.S. population has been calculated after every U.S. Census since 1790. If the United States map was a scale and every person had equal weight, the center of population is the place where the scale would balance.This display, which also includes a more detailed map of the center of the population in Indiana in 1890, was featured in the Statistical Atlas of the United States, Based Upon the Eleventh Census and illustrates the dynamic changes in population occurring in the decades following the Civil War. The map clearly illustrates the westward movement of the population between 1790 and 1890, as the United States expanded its territory and the American frontier disappeared. However, in his explanation of the map, Geographer Henry Gannett commented much more extensively on the center's movement north and south. He described the center moving “sharply northward” from 1860 to 1870, “due in part to waste and destruction in the south consequent upon the civil war, and in part probably to the fact that the census of 1870 was defective in its enumeration of the southern people, especially of the newly enfranchised colored population” (p. 9). Of the 1880 center of population, Gannett stated that it had “returned southward,” partly because of the imperfect 1870 Census, but also because the population of the southern states “increased greatly, both from natural growth and from southward immigration” (p. 8). However, of the center’s shifting movement between 1880 and 1890, Gannett spoke of population growth and urbanization in the North, writing, “The most salient point of progress during the past decade is the northing which has been made, which is doubtless due to the great development in the cities of the northwest and in the state of Washington, and in no small degree to the increase in population in New England” (p. 11). Accompanying the map in the Atlas, is also a table with each center's geographic coordinates, location relative to an important town, and movement in miles since the last Census.