I have information on a William Josiah Jefferson b 1871 in Des Moines Co Iowa. He was my grandfather. His father was William Jefferson b 1834 Marshall co WV and moved to IA after the civil war. There were other Jeffersons in Des Moines Co IA that moved to IA before the civil war. I have found a Briant Jefferson that must be related but I can't find the connection. My William Joshia Jefferson moved to Custer Co MT between 1884-1891 and worked with mules at Ft. Keough. His mother died when he was 2 and he was given to one neighbor, then another finally living with Mrs. Elizabeth Newsom as an 'adopted son' in page co Iowa in 1880. He said he ran away at 13 and went to MT. I have done lots of research on this line and I am not related to Pres. Jefferson.
None of this may help but thought I'd give you some new places to look. Mary Ellen firstname.lastname@example.org