James came over to Scotland with his Irish wife, Agness, before the birth of their first child who was born in Glenluce, Wigtownshire, Scotland in 1839. They emigrated just before the Irish Potato Famine which was between 1845 and 1850. The prime purpose was almost certainly to find agricultural work.
Why choose Wigtownshire ? The answer is that because a lot of the Irish immigrants were poor, they tended to stay where the ship took them and therefore the west coast of Scotland, particularly Wigtownshire, was heavily populated by the Irish.
Census show that James was an agricultural labourer and his wife a sower of muslin.
They certainly moved around over their lifetime, but always within about a twenty mile radius. They were probably not able to write their names as the spellings on the various census made them tough to trace and the variations suggest they may have had a strong accent :
1839 McTEAR - Glenluce (birth of first child)
1841 McTIER - Kirkinner
1851 McINTYRE - Portpatrick - Craigoch Park Cot House
1861 McFEAR - Penninghame - Barnvennan Cottage
1871 McLEAR - Mochrum - Cornhalloch Cottage
1881 McTIER - Mochrum - Free Church Manse (James was described as a border)
I have not been able to find the deaths of either James or Agness, although Agness died between 1871-81 and James died after 1881.
Photo credit : Wikipedia - Emigrants Leave Ireland by Henry Doyle 1868