Recently a Cameron researcher sent me a few bits of additional information on an early settler named Mordecai Cameron. I've added this comment on the original post but there is also a scanned image which I'm placing here. Thanks so much to Virgil Cameron.
This is what Virgil emailed:
Starting with Mordecai's son John Cameron. Although several sites list him as John H. Cameron, his real name was John Eagan Cameron. I am attaching a photo of his Baptismal Record that I photographed from the actual document at the Donegal Presbyterian Church in PA. Mordecai also had a daughter Harriet christened at the same church in 1811. Mordecai stayed close to his half brother Charles early on but eventually moved West THROUGH Virginia (now West Virginia) where Samuel Cameron was born in Kingwood, Preston Co.
I researched tax records and census records to prove residency of these early years.
Other Items of note:
Charles (Mordecai's half brother) was the father of Simon Cameron, Secretary of War for Lincoln. (Although Simon was raised by foster parents)
Simon (Mordecai's father) had a revolutionary war record of being fined for not marching when called. His case was dismissed because he said: "I speak no English, only Gaelic and my wife recently died leaving me 4 small children" and he agreed to march when next called.