The “Statistics of U.S. Businesses” is published annually from the Census Department. From the site, “It includes statistical data on number of business firms, the number of establishments, employment, annual payroll, and estimated receipts for most U.S. business establishments. The data is tabulated by geographic area, industry, and enterprise size.” The statistics are also listed for the entire country, by state, county, and Metropolitan Statistical Area (MSA). Employment and payroll are some of the main areas covered. Many of the statistics are shown on Excel tables.
Historical statistics are shown here. These statistics are done annually as well and go back to 1997.