According to the Nova Scotia censuses it is in Digby Nova Scotia where Isaac Leeman settled after he left the States.
On the 1871 census he was there with his wife Amelia and then in 1881 she was widowed and living with Robert and Rachel Outhouse her parents. Amelia having with her a Leeman daughter by the age of 9 yrs old this means that Isaac died in between 1872 and 1881.
Deaths' records are missing for Nova Scotia from 1878 to 1890.
Good luck in your researches!