James Buchanan, Jr. (April 23, 1791 – June 1, 1868) is the 15th President of the United States (1857–1861).

He is the only president from Pennsylvania, the only president who remained a lifelong bachelor, and the last president born in the 18th century.

He represents Pennsylvania in the U.S. House of Representatives, and later the Senate, and serves as Minister to Russia under President Andrew Jackson.

He is also Secretary of State under President James K. Polk.

After he turns down an offer for an appointment to the Supreme Court, President Franklin Pierce appoints him Minister to the United Kingdom, in which capacity he helps draft the controversial Ostend Manifesto.

Buchanan is nominated in the 1856 election.

Throughout most of Franklin Pierce's term, he is stationed in London as a Minister to the Court of St. James's and therefore is not caught up in the crossfire of sectional politics that dominates the country.

Buchanan is viewed by many as a compromise between the two sides of the slavery question.

His subsequent election victory takes place in a three-man race with John C. Frémont and Millard Fillmore.

As President, he is often called a "doughface", a Northerner with Southern sympathies, who battles with Stephen A. Douglas for the control of the Democratic Party.

Buchanan's efforts to maintain peace between the North and the South alienate both sides, and the Southern states declare their secession in the prologue to the American Civil War.

Buchanan's view of record is that secession is illegal, but that going to war to stop it is also illegal.

Buchanan, first and foremost an attorney, is noted for his mantra, "I acknowledge no master but the law."

When he leaves office, popular opinion has turned against him, and the Democratic Party has split in two.

Buchanan had once aspired to a presidency that would rank in history with that of George Washington.

However, his inability to impose peace on sharply divided partisans on the brink of the Civil War has led to his consistent ranking by historians as one of the worst Presidents.