Also available at HC 101 .A184 (for 1964 - 1997).
Arranges by NAICS code data by county. The data for each industry include "number of employees, taxable payrolls, and number of establishments by employment size class." There are volumes for the separate states and a summary volume for the U.S. as a whole.
To access it, click on advanced search and then on show; me all; under topics choose datasets (expand by clicking on +);