U.S. Census Office, Map of Predominating Sex Showing the Local Excess of Males or of Females in the Distribution of Population (1874)

This choropleth map illustrates the predominating sex across the United States in 1870. Darker shading indicates a higher percentage of men, while areas shaded in white represent a higher percentage of women. The darkest shading identifies regions where the population of men was at least 20 percent higher than the population of women. States with the highest proportions of men were primarily in the Midwest, including Wisconsin, Illinois, Missouri, Minnesota, Kansas, and Michigan. Many of these states lay along the frontier of westward expansion, where men were drawn by employment opportunities in male-dominated occupations such as surveying, logging, and farming. In contrast, many southern states—including Georgia, North Carolina, South Carolina, Alabama, and Tennessee—had higher proportions of women. This likely occurs due to a lost generation of young men who fought in the Civil War. This map was included in the Statistical Atlas of the United States based on the Results of the Ninth Census, a compilation of data visualizations published in 1874 under the direction of Francis A. Walker to present information collected from the 1870 Census in visual form.