Hi Laraine, William Melville Alison caught my eye. Captain Harry Alison, my ggg grandfather was bporn 1795 in Muthill, Perthshire, Scotland. I have detailed information on him and I have found cousins from his nine surviving children in the US and Canada so far.
He was related to a Lord Melville, whose actual name was Henry Dundas. He sponsored his commision in the 90 Regiment of Foot.
I doubt that Williams second name is a coincidence, i.e. if he is related to Lord Melville, than you are related to me.
If you would like more information, my address is as follows.
George McCabe Bancroft ON Canada firstname.lastname@example.org