This response, rather than on the Jongebloed Family Finder FTDNA match that I have, is geared more toward my husband and the McKee surname.Albeit in a round about manner.You mention SISSON and MCKAY in your message to which I am replying here.
Being an admin on the FTDNA McKee Group I have some family records of our various members, wish I had them all, and we have a member who has SISSON..........a Charlie Sisson McKee born 1867 at Chambers, Alabama.
Do you think perhaps there might be a link there for you?Rather than McKay it could have been McKee in your family.This happens a lot depending on where the emigrants came from within their country of origin and if was Scotland or Ireland at any given time and how they pronounce their name, not to mention how the local clerk or clergy or census taker could or, more often, could not spell.
I will forward this link to the McKee and you can let me know here if you think there may be a connection.
On the Jongebloed that would be on my lineage and I will make a different post on that.Linda Stanfill McKee