During non-filer examinations, the examiner will determine if related returns (corporate, partnership, employment tax, and excise tax returns) have been filed as required.

FORBES: Non-Filers Beware: Who's That Knocking at Your Door ?

The appendix has a number of informative tables and charts giving data from 1950-2009 for (1) individual income tax, (2) corporate income tax, (3) employment taxes, (4) excise taxes, (5) estate and gift taxes, and (6) other receipts.

FORBES: JCT Summarizes Federal Estate And Gift Taxes From 1975-2011

Until 1936, the federal excise tax generated more revenue than the federal personal income tax and the federal corporate income tax combined.

FORBES: Soak-The-Rich Taxes Soak Everyone