John J. Jacob holds a foundational background in law and education, having practiced law and taught in various capacities before entering politics. He earned degrees from Dickinson College and later taught at the University of Missouri. Jacob's career in public service began during the American Civil War, and he transitioned into elected office in the late 1860s. He served as governor, where he focused on education reform, civil rights, and constitutional changes, including the expansion of the governor's term to four years. After his governorship, Jacob continued to serve in the state legislature and as a circuit judge.

John J. Jacob's political identity is marked by a blend of progressive education reform and a nuanced approach to post-war reconciliation. He championed the establishment of facilities for the mentally handicapped and teacher training schools, yet his efforts to eliminate discriminatory legislation against former Confederates reveal a complex stance on civil rights. Jacob's tenure saw a significant constitutional shift to balance legislative and executive powers, showcasing a calculated approach to governance. His support for judicial independence, despite facing opposition, adds another layer to his ideological agility.