After a little more searching, I found the following.

1. 1850 US Census for Rapides Parish - 1 George Kelso (6 yo mulatto) living in Rapides Parish with Mary (35 yo) and Rebecca (32 yo) Kelso, mulattos. George was born in LA, but his father was from Maryland. No male adult was listed as living at this residence.

2. 1860 US Census Slave Schedule - 1 George Y. Kelso (17 yo mulatto) living in Rapides Parish, who is listed as a planter who is the owner of about 100 slaves. (On the 1860 document, the web site says George W. Kelso, but if you read the original, it is clearly George Y. Kelso)

3. Also, I found a George E. Kelso (17 or 18 yo mulatto) in the Calcasieu Parish 1860 US Census Slave Schedule who is listed as a planter who is the owner of about 100 slaves.

4. Neither of the men mentioned as mulatto owners of slaves in 1860, is listed in the regular census.

5. By 1891, George Y. Kelso is listed (Residence document) as living in New Orleans, where he is an import tax collector (Federal job?).

There do not seem to have been two (2) George Kelsos living in Rapides Parish. The George Y. (Rapides Slave Schedule) versus George E. (Calcasieu Slave Schedule), however, is puzzling - same person, same 100 slaves, two parishes (abutting at the time)?? I almost wonder if this is a Census "fraud" effort to raise the LA vote count (each slave counted as 3/5th of a person in determining Federal representation for the State).

Hope this helps - It only seems to cloud your quest.

Very best

Don Parker