John Wesley Blackman was born around 1813 in Maine. He married Sylvia Campbell sometime in the 1830s, and they had at least six children: Bradley, born around 1838; Almon, born around 1842; Charles, born around 1846; Athiel, born around 1849; Horace, born around 1853; and Sylvia, born around 1858.
They lived in Eddington, Maine, and Blackman worked as a farmer. By 1850, they owned $600 of real estate. A decade later, their wealth had grown to $1,500 of real estate and $550 of personal property. He owned 275 acres of land, and he produced 60 bushels of corn and 90 bushels of oats in 1859. In 1870, he owned $2,700 of real estate and $925 of personal property. He died in Eddington on January 13, 1886.