Although the U.S. Census Bureau carries out hundreds of surveys every year, its most well-known duty is still to conduct the decennial census. Census results have several high profile applications: they are used to reapportion seats in the House of Representatives, to realign congressional districts, and as a factor in the formulas that distribute hundreds of billions of dollars in federal funds each year. Because of the importance of this population count, procedural changes in the decennial census often reflect larger organizational shifts at the Census Bureau.
This section follows the evolution of the decennial census by detailing the events surrounding each of them. Political and technological changes, and the shifting public demand for information, have all shaped the modern census and the mission of the Census Bureau.
Census Day was June 1, 1870.
||U.S. Resident Population
||Population per square mile of land area
||Percent increase of population from 1860 to 1870
||Number of States
Data tables for years 1790 through 1930 will be found in the library publications section for that specific year.
About the 1870 Decennial Census
Read an overview of the 1870 Census, including information on authorizing legislation, enumeration, technological advancement, & more.
1870 Decennial Census Historical Facts
Get a quick portrait of the U.S. by decade with pop culture milestones, population highlights, census details, and the 10 largest urban places.
1870 Decennial Census Official Publications
Official publications released by the U.S. Census Bureau have a report number and often list the lead author(s).
1870 Decennial Census Questionnaires & Instructions
Learn how the Decennial Census questionnaires have changed through the decades and download questionnaires from each Census decade.