It would have been possible for America to avoid an "unnecessary war" if James Buchanan had been a stauncher executive. There were other insufficient leaders prior to his presidency, but Buchanan was the weakest, and failed in avoiding a civil war. He was indecisive and a compromiser, unwilling to choose a side or express opinions. His presidential aspirations consisted of getting through the national crisis and leaving the dirty work for his successor. In Allan Nevins's "The Needless Conflict", he explains why a firmer Buchanan could have avoided the Civil War by stopping disunion before it escalated.
Though "everyone knew that a heavy majority of the Kansas settlers were antislavery", the proslavery crowd made a tough fight. The reason for the struggle mainly rested on Buchanan's shoulders. The Kansas-Nebraska Act resolved for popular sovereignty, and its author, Stephen A. Douglas, wanted to take all measures to ensure this. He convinced Buchanan to appoint Robert J.
Walker as governor of Kansas, with orders that "the constitution be laid before the people". When the people of Kansas rejected the Lecompton Constitution, a proslavery constitution, Buchanan still tried to ram it down the congress's throat. He upheld it as long as possible, giving the southern proslaveryites time to gain "fresh strength".
Nevin's subtitle states, "If Buchanan had met the Kansas Problem firmly we might avoided the civil war". The reasoning for this is that he could have halted the quarrels before anything really intensified. The proslavery forces were weak and if Buchanan would have put his fist down early than America could have evaded the Civil War. It is for this role that Buchanan can be "counted one of the signal failures of American statesmanship".
James Buchanan's indecisiveness brought forth other "aftereffects" as well. It paved the way for the Republic party, "which...