Slavery made the presidency an incredibly difficult task in the mid-19th century. The debate over it disrupted American society. In this volatile atmosphere, strong presidential leadership might have saved the nation from civil war if it had been exercised early and firmly enough to warn off radicals on both sides. By refusing to take a firm stand on either side of the slavery issue, Buchanan failed to resolve the question, leaving his nation's gravest crisis to his successor. Indeed, Buchanan's passivity is considered by most historians to have been a prime contributing factor in the coming of the Civil War. To many, Buchanan seemed like a Northerner in name only: He openly despised abolitionists. Southerners were his political and social friends, and when forced to take sides in one of the endless slavery battles, he typically sided with Southern interests.

James Buchanan was a talented and skillful politician. He also was honest, had considerable legal ability, and could balance varying coalition agendas. In a different time, he might have been a successful President, but he was no match for the forces that tore at the country in the late 1850s.