The National Histiorical Geographic Information System (NHGIS) includes Decennial Census data from 1790-2010, as well as selected data from the American Community Survey, County Business Patterns, Census of Religons, Special city Censuses of Chicago & Detroit and more. All of this data is available for download along with the accompanying boundary files. This is the easiest way to import and use Census data in ArcGIS. Refer to the directions below for importing and joining tables with geographic boundaries. Free registration is required to download data.
Don't forget to check out the Neighborhood and Community Census Data page for information on how to study neighborhood and other local boundary areas using Census data.
Urban Policy and the Census by 
Unlocking the Census with GIS by 