He was the son of Jacob Miller McCormick, a veteran of the War of 1812 and prominent Ithaca resident, and Catherine Conrad.
His paternal great-grandfather was Joseph McCormick, a Scotch-Irish immigrant who lived near the Giants' Causeway in County Antrim and came to America in 1760.
In 1856, he moved to Port Jervis, initially as a fuel agent for the Delaware Division and later as resident engineer and paymaster.
[1] In 1870, McCormick permanently moved to Port Jervis, where he worked in the real estate and insurance business and dealt in musical instruments.
He served a number of local offices, including village president, a member of the board of trustees, justice of the peace, sewer commissioner,[1] village treasurer, a member of the board of education, chief engineer of the fire department,[3] and police justice.