John G. McCullough graduated first in his class from Delaware College and earned a law degree from the University of Pennsylvania. He practiced law in California and was admitted to both the California and Pennsylvania Supreme Court bars. McCullough transitioned from a legal career to politics, serving in the California State Assembly and as Attorney General. He later moved to Vermont, where he held various executive roles in the railroad industry and became active in the Republican Party, serving as a state senator and governor. McCullough's career also included significant involvement in banking, railroads, and insurance sectors, and he supported the transition from statewide prohibition to a local option law in Vermont.

John G. McCullough's political identity is marked by a blend of business acumen and local governance. His strategic philosophy seems to prioritize regional industrial interests, as evidenced by his support for a local option law on prohibition in Vermont. McCullough's approach to economic policy is deeply intertwined with his business career, suggesting an ideologically agile stance that balances corporate interests with state governance. His rhetoric likely emphasizes stability and regional autonomy, raising intriguing questions about the interplay between his business ventures and public policy decisions.