John McCollum (b)25 Dec 1770 in NJ married Jane (Hamson) Ayers in June 1798. June had 5 children from previous marriage. John and June had the following children: twins David and Mary; Robert; John; Daniel; Anna; Ira; and Harvey (b)1813 who must be the father of your Harvey McCollum. From the History of Trumbull and Mahoning Counties.. "John McCollum bought the first land in Austintown Twp (once Trumbull then later Mahoning County OH) in 1798 and erected a cabin which was later owned by Harvey McCollum. (the father of yours) John McCollum was in the War of 1812. He died 1849. I have no idea when John and Jane moved from NJ to OH. Hope this helps you in your research. I have no further info.