After attending Knox College in Galesburg, Illinois, for one year, Buford was accepted into the Class of 1848 at the United States Military Academy (West Point). Upperclassman during Buford's time at West Point included Fitz-John Porter (Class of 1845), George B. McClellan (1846), Thomas J. Jackson (1846), George Pickett (1846), and two future commanders and friends, George Stoneman (1846) and Ambrose Burnside (1847). Buford graduated 16th of 38 cadets and was commissioned a brevet second lieutenant in the 1st U.S. Dragoons, transferring the next year to the 2nd U.S. Dragoons. He served in Texas and against the Sioux, served on peacekeeping duty in Bleeding Kansas, and in the Utah War in 1858. He was stationed at Fort Crittenden, Utah, from 1859 to 1861. He studied the works of General John Watts de Peyster, who urged that the skirmish line become the new line of battle.
Throughout 1860, Buford and his fellow soldiers had lived with talk of secession and the possibility of civil war, and when the Pony Express brought word that Fort Sumter had been fired on in April 1861, that possibility became a reality. As was the case with many West Pointers, Buford had to choose between North and South. Based on his background, Buford had ample reason to join the Confederacy. He was a native Kentuckian, the son of a slave-owning father, and the husband of a woman whose relatives would fight for the South, as would a number of his own. On the other hand, Buford had been educated in the North and come to maturity within the Army. His two most influential professional role models, Colonels Harney and Cooke, were Southerners who elected to remain with the Union and the U.S. Army. He loved his profession and his time on the frontier had snapped a number of threads that drew other Southerners home.
John Gibbon, a North Carolinian facing the same dilemma, recalled the evening that John Buford committed himself to the Union:
130 years latter he will be portrayed in a movie about Gettysburg by veteran western actor Sam Elliot.One night after the arrival of the mail we were in his (Buford's) room, when Buford said in his slow and deliberate way "I got a letter from the Governor of Kentucky. He sent me word to come to Kentucky at once and I shall have anything I want." With a good deal of anxiety, I (Gibbon) asked "What did you answer, John?" And my relief was great when he replied "I sent him word I was a Captain in the United States Army and I intended to remain one"