Born October 15, 1838, Isaac Charles Parker was the youngest son of Jane and Joseph Parker. He was born and raised outside Barnesville, in Belmont County, Ohio. Still on the edge of the frontier in the early 1840s, southeastern Ohio was primarily an agricultural area.
While raised on a farm, Isaac cared little for working out of doors. His mother, Jane Shannon Parker, was the niece of the governor, and figured prominently in raising her son. When not required on the farm, he attended the Breeze Hill primary school. After completing his primary education, he attended the Barnesville Classical Institute, a private school. It was said that he was, "always a hand to get an education;" and in order to pay for his higher education he taught in a country primary school.
At the age of seventeen, Isaac Parker decided to study law. His legal training consisted of a combination of apprenticeship and self directed study. Isaac read law with a Barnesville attorney, passing his bar exam in 1859.