black-owned businesses as a share of total, by state
I'm hoping to find the share of African-American owned businesses in each state, and nationally, for as many years as the data exists. I spent about 1.5 hours on the phone with someone at the Census to get one year of information, so I'm hoping you might have it in a bit more accessible form.
Multiple sources must be used to compile a picture of the Black-owned businesses by state. The Survey of Minority-Owned Business Enterprises (first conducted in 1969) and Survey of Business Owners collected data on the demographics of owners of business enterprises every five years in years ending in 2 and 7. They were replaced by the Annual Business Survey in 2017. You can find the full text of the older volumes in the HathiTrust database or on the Census Bureau website. Black-owned businesses by state are listed in a publication with the number MB[year]-1. For example, the report for 1992 is MB92-1 and also includes data for 1987.
Here are links for the publications that give numbers of Black-owned businesses by state. Unfortunately, they do not always give the number as a percentage of all businesses for each state. To derive that number, you would need to get the total number of business enterprises in each state from the main Survey of Business Owners page for each year or from the Statistical Abstract of the United States.
The data for 2012-present is available in dynamically-generated tables rather than static publications.