from their web page: "The National Historical Geographic Information System (NHGIS) is a project to create and freely disseminate a database incorporating all available aggregate census information for the United States between 1790 and 2015." Free account creation required.
Creator
NHGIS
Date of creation
1790
Data edited date
2015
Temporal extent
1790 to 2015
Publisher
NHGIS
Data type
Require acknowledgement to use
None
Cost for use
None
Medium
web
Open data
Restrictions
Public
Index link