"The Rich's of McKinney, TX."

I am researching the Rich's that once lived in McKinney Tx. I have been able to go back to 1831 to Killian Rich, however I don't know where he came from. I am also researching Army Lee Blankenship family from the same area. I understand the family survived the Trail of Tears. Any information would be greatly appreciated. I am willing to share the information I have gathered.