Yes, all of Richard Devan's children show as born in MO which I don't understand since there are no slave owners named Devan in the 1860 or 1850 census. It was Richard Devan that I read as born in Maryland. It maybe Missouri however that just makes the mystery worse since that would have meant that Richard was born a slave in 1801 in Missouri.

Richard Devan married or had his marriage to Mahala validated in 1865 in Cape Girardeau MO by the chaplin of the freedman's bureau. At the time of the marriage it shows they have 7 children. Joseph Devan (my ancestor) was one of them. On that same record a Hannah Devan who was 16 at the time had her marriage validated to an Elbert Penney. Now I can find "Penney" slave owners in Missouri. And of my relatives verified that they were distant cousins to some Penneys however that still doesn't explain where Richard Devan was from or who owned him. Mahala's maiden name was Hill and she moved to and lived with Joseph Devan in Illinois when the family migrated there.

The sons were coal miners and worked the coal mines in Illinois and then Iowa (in the famous Buxton, IA).

In terms of other actual records, no I find none. One answer might be that Richard Devan and Mahala Hill are not the parents of those 7 children and that is quite possible because Richard was 64 and Mahala was 49 in 1865 and the oldest of the 7 children was just 18. So they may have been born in Missouri and Mahala was born in Alabama but Richard is a hard nut to crack.