This is an ancient Scottish locational surname. It is either from the town of Kelso in Roxburghshire, or an estate known as Kelsoland. It is also one of the earliest recorded surnames not just in Scotland but the whole British Isles, the name holders holding various positions of prominence in medieval times.
Locally (In Scotland) the name is known as Kelsae, thought to be derived from the Scots "Chalk Hill" in reference to the chalky soil of the land near the river at the west of the town.
A lot of African-Americans have surnames that were from their slave owners. Kelso is not one of those names. In my case, this is a family name. Kelso was the last name of my great-great grandfather who was Scottish and lived in Upstate New York. The name has made it all the way down to me and it will die with me in this line. My brother, who would have been able to continue the line died many years ago.
As long as I am alive, I will wear the name proudly. When I got divorced I took my last name back. And If I ever marry again, I will not change it. This will be the name engraved on my tombstone.