From the U.S. Government Documents at Columbia University Libraries: Columbia University has been a U.S. Federal government depository since 1882. CLIO has records for print and electronic government information. Use these links to search CLIO with government filters applied:
For example, try this search for the United States Sentencing Commission guidelines manual.
See also Columbia University Library's extensive research guides on government documents:
United States - Federal
United States - State & Local
One more way to search census information is to use the Library's Ancestry subscription: