The paper, which was all handwritten, was in a ledger with files from John Kean, a delegate to the 1787 Constitutional Convention, according to the report. A heading on Kean’s enumeration says it was presented to the Constitutional Convention. The count appears to have been conducted by the states separately between 1781 and 1786, apparently in person.
According to the document, there were 2.2 million whites and Indians and 567,000 blacks. Virginia had the most people — 530,000 — and New Jersey had nearly 150,000.
You can read more in an article by Sam Roberts published in the New York Times at http://www.nytimes.com/2010/05/19/nyregion/19kean.html
My thanks to Greg Thiel for telling me about this article.