Your question actually comes in two forms:
1. How many companies?
2. How many corporations?
Companies can be limited partnerships or even individual
proprietorships. But for good answers to either you want the
Statistical Abstract of the United States. And specifically you want
the Business Enterprise section. You can find several years of
U.S. Census Bureau
Statistical Abstract of the United States
Specifically the 2004 Statistical Abstract shows the following
increases in corporations filing tax returns. It would exclude any
corporations registered and inactive. The data?s from the Internal
Note that 2001 is the most-recent year for which there is data.
2004 Statistical Abstract of the United States
?Corporations: 1990 ? 2001? (chart 725)
I think that you?ll find the Statistical Abstract helpful too if
you?re looking at other information, such as company sizes, industries
and classifications of non-incorporated businesses.