I am not familiar with your Simon.However, I do have one Simon Overholt (Philip, Joseph, Isaac) in my file who was born ca 1860-65 in Louth Twp., Lincoln Co., Ontario and died 28 Jan 1899.He married Alice Clark on 31 Jan 1898 in St. Catharines.
Philip Overholt (Joseph, Isaac) was born 4 Jul 1826 in Louth Twp. and died 4 Sep 1894 in Louth.He married Anna Elizabeth Young ca 1850.
Joseph Overholt (Isaac) was born 23 Apr 1791 in Frederick Co., Maryland and died 28 Aug 1868 in Louth Twp.He married Mary ________.
Isaac Overholt was born 1741-46 in Bucks Co., Pennsylvania and died in 1824 in Louth Twp.
I am not aware of any of these folks being of African ancestry, however, I shall double check and get back if I find anything of further interest.