Looking for Smith John from Ireland

Hello,
I am trying to find any information possible on John Smith born abt. 1851, Northern Ireland. He was married to Margaret Kennan, born abt. 1856 Northern Ireland. I believe they had 10 children: Thomas b. 1881, Barbara Alice b. 1875, Samuel Homer b. 1883, Elizabeth Margaret b. 1887, William James b. 1875, Amanda b. 1896, Frederick Hugh Harris b. 1892, Mary b. 1885, Emma b. 1890, and Louisa Jane b. 1894.

Any information on any of the family members would be very helpful or any clues on where I could look would be greatly appreciated.

Thank you!