Born into a large Irish Catholic family on a farm in the Margaree Valley of Cape Breton, Nova Scotia, Moses was the eldest boy in a family of twelve. As a youth he was very concerned at the scale of outmigration from the valley: young men and women leaving for the steel mills and coal mines, or taking up jobs as domestics in the "Boston States". He determined he would get a good education so he could help people make their farms more profitable and give them a reason to stay on the land.