James Buchanan was born in a log cabin at Cove Gap, near Mercersburg, Franklin County, Pennsylvania, on April 23, 1791. He died on June 1, 1868. He was the second of ten children born to James Buchanan and Elizabeth Spear, two of whom did not survive past infancy. The Buchanan family directly descends from King James I of Scotland.

In 1802, he moved to Mercersburg with his parents, where he was privately tutored. He later attended the village academy and graduated from Dickinson College, in Carlisle, Pennsylvania. At one point, he was expelled from Dickinson for wild behavior and bad conduct, but after pleading for a second chance he graduated with honors.

Buchanan began to study under the prominent Lancaster lawyer James Hopkins. After being admitted to the Pennsylvania Bar in 1812, he quickly gained prominence and was elected to the Pennsylvania House of Representatives in 1814 and 1815 as a Federalist. Thus began Buchanan's long career as a public servant. In 1820 he was elected to the U.S. House of Representatives. With the extinction of the Federalist Party in 1824, he joined the Democrats. In Congress, Buchanan was an active opponent of John Quincy Adams and the Panama Mission. He supported Andrew Jackson in the election of 1828, and this support led to his appointment as the chairman of the Committee on Judiciary. In 1831 Jackson appointed him minister to Russia. On his return to the United States, Buchanan was elected to the U.S. Senate; he was reelected in 1837 and again in 1843. By this time, he had gained national prominence in the Democratic Party. He was passed over for a presidential nomination in both 1844 and 1848, but he received prominent appointments, serving as Secretary of State under James Polk and as minister to Great Britain under Franklin Pierce.

In 1856 Buchanan was finally nominated for the presidency, with John C. Breckinridge of Kentucky as his running mate. The campaign platform was based on the finality of the Compromise of 1850 and the non-intervention of Congress concerning slavery in the territories. Buchanan defeated opponent John Fremont in the electoral college, though he failed to receive a majority of the popular vote. Buchanan's presidency was a stormy one, filled with controversy and numerous domestic difficulties. By the end of his term, the slavery issue and states' rights problems had caused serious divisions in government circles.

The Dred Scott court case occurred at the beginning of his administration which stated that slaves were considered property. Despite being against slavery himself, Buchanan felt that this case proved the constitutionality of slavery. He fought for Kansas to be entered into the union as a slave state but it was eventually admitted as a free state in 1861. In 1857, an economic depression occurred called the Panic of 1857. The North and West were hit hard but Buchanan took no action to help alleviate the depression.

When it was time for reelection, Buchanan had decided not to run again. He knew that he had lost support, and he was unable to stop the problems that would lead to secession.

In November, 1860, Republican Abraham Lincoln was elected to the presidency immediately causing seven states to secede from the Union forming the Confederate States of America. Buchanan did not believe that the federal government could force a state to remain in the Union. Afraid of Civil War, he ignored aggressive action by the Confederate States and abandoned Fort Sumter. He left office with the union divided.

Buchanan retired to his Lancaster estate, called Wheatland. He supported Abraham Lincoln throughout the Civil War and on June 1, 1868, he died of pneumonia.

He was the only President single President, having been engaged to Anne C. Coleman, who died before they had the opportunity to get married.