He was a land stewart, lived in townland of Killabrick, as did Martha. Married in E.Truagh 28th Sept 1855. A land stewart would have been responsible for day to day running of farm, keeping eye on tenants, maybe collect rent...
Don't know why they married in ET as Donaghmoyne would be their parish (for Killabrick) as far as I know. Errigal Shanco was just down the road, eventually closed and combined with ET but Hetherington wasn't a very common name there either.