Dion Haco’s “J. Wilkes Booth, the Assassinator of President Lincoln” is probably the first post-assassination full-length book with John Wilkes Booth as its central character.
After Haco’s novel, war correspondent George Alfred Townsend wrote probably the first book-length biography of Booth, “The Life, Crime and Capture of John Wilkes Booth.”
Both books were advertised by May 24, less than a month after Booth was shot to death at the Garrett Farm in Virginia.
Source: Books at Iowa 2 by Ronald L. Fingerson