Well, his parents wouldn't be slaves in 1870.I would take the 1870 census index, look up every Booker family, check each of them for having a son named Othello Claude Booker, or similar name that could be a nickname, and about 4 years old.
I looked up every Burnett family for 1860 MO, looking for one that had a daughter named Ellen, and I didn't even know her age.I found her.Yes, it takes some time, but it paid off BIG.You do have the advantage the family will be black and matchthat with the unusual name of Othello.Just so it isn't soooo unusual the census enumerator has trouble spelling it.(^_^)
Using this same procedure for all Meek families in 1860 IL, I think I've found the family of John Henry Meek, but can't find them on 1870 and by 1880 he's in TX and married.So, haven't proved that one, YET.
I've noticed many of the GenWeb counties in Southern states are coming up with more information/sources that might be espescially helpful for black research.