Thomas Woodrow Wilson (December 28, 1856 – February 3, 1924) was the 28th president of the United States, serving from 1913 to 1921. He was the only Democrat to serve as president during the Progressive Era when Republicans dominated the presidency and legislative branches. As president, Wilson changed the nation's economic policies and led the United States into World War I. He was the leading architect of the League of Nations, and his stance on foreign policy came to be known as Wilsonianism.

Born in Staunton, Virginia, Wilson grew up in the Southern United States during the American Civil War and Reconstruction era. After earning a Ph.D. in history and political science from Johns Hopkins University, Wilson taught at several colleges prior to being appointed president of Princeton University, where he emerged as a prominent spokesman for progressivism in higher education. Wilson served as the governor of New Jersey from 1911 to 1913, during which he broke with party bosses and won the passage of several progressive reforms.

In the 1912 election, Wilson defeated the incumbent Republican president, William Howard Taft, and the third-party nominee and former president Theodore Roosevelt, becoming the first Southerner to win the presidency since 1848. During his first year as president, Wilson authorized the widespread imposition of racial segregation inside the federal bureaucracy, and his opposition to women's suffrage drew protests. His first term was largely devoted to pursuing the passage of his progressive New Freedom domestic agenda. His first major priority was the Revenue Act of 1913, which began the modern income tax, and the Federal Reserve Act, which created the Federal Reserve System. At the outbreak of World War I in 1914, the U.S. declared neutrality as Wilson tried to negotiate peace between the Allied and Central Powers.

Wilson was narrowly re-elected in the 1916 election, defeating the Republican nominee, Charles Evans Hughes. In April 1917, Wilson asked Congress for a declaration of war against Germany in response to its policy of unrestricted submarine warfare that sank American merchant ships. Wilson concentrated on diplomacy, issuing the Fourteen Points that the Allies and Germany accepted as a basis for post-war peace. He wanted the off-year elections of 1918 to be a referendum endorsing his policies, but instead the Republicans took control of Congress. After the Allied victory in November 1918, Wilson attended the Paris Peace Conference, accompanied by his most important adviser, Colonel Edward House. Wilson successfully advocated for the establishment of a multinational organization, the League of Nations, which was incorporated into the Treaty of Versailles that he signed; back home, he rejected a Republican compromise that would have allowed the Senate to ratify the Versailles Treaty and join the League.

Wilson had intended to seek a third term in office but had a stroke in October 1919 that left him incapacitated. His wife and his physician controlled Wilson, and no significant decisions were made. Meanwhile, his policies alienated German- and Irish-American Democrats and the Republicans won a landslide in the 1920 election. In February 1924, he died at age 67. Into the 21st century, historians have criticized Wilson for supporting racial segregation, although they continue to rank Wilson as an above-average president for his accomplishments in office. Conservatives in particular have criticized him for expanding the federal government, while others have praised his weakening the power of large corporations and have credited him for establishing modern liberalism.

Thomas Woodrow Wilson was born to a family of Scotch-Irish and Scottish descent in Staunton, Virginia. He was the third of four children and the first son of Joseph Ruggles Wilson and Jessie Janet Woodrow. Wilson's paternal grandparents had immigrated to the United States from Strabane, County Tyrone, Ireland, in 1807, and settled in Steubenville, Ohio. Wilson's paternal grandfather James Wilson published a pro-tariff and anti-slavery newspaper, The Western Herald and Gazette. Wilson's maternal grandfather, the Reverend Thomas Woodrow, moved from Paisley, Renfrewshire, Scotland, to Carlisle, Cumbria, England, before migrating to Chillicothe, Ohio, in the late 1830s. Joseph met Jessie while she was attending a girl's academy in Steubenville, and the two married on June 7, 1849. Soon after the wedding, Joseph was ordained as a Presbyterian pastor and assigned to serve in Staunton. His son Woodrow was born in the Manse, a house in the Staunton First Presbyterian Church where Joseph served. Before he was two years old, the family moved to Augusta, Georgia.

Wilson's earliest memory of his early youth was of playing in his yard and standing near the front gate of the Augusta parsonage at the age of three, when he heard a passerby announce in disgust that Abraham Lincoln had been elected and that a war was coming. Wilson was one of only two U.S. presidents to be a citizen of the Confederate States of America; the other was John Tyler, who served as the nation's tenth president from 1841 to 1845. Wilson's father identified with the Southern United States and was a staunch supporter of the Confederacy during the American Civil War.

Wilson's father was one of the founders of the Presbyterian Church in the Confederate States of America, later renamed the Presbyterian Church in the United States (PCUS), following its 1861 split from the Northern Presbyterians. He became minister of the First Presbyterian Church in Augusta, and the family lived there until 1870. From 1870 to 1874, Wilson lived in Columbia, South Carolina, where his father was a theology professor at the Columbia Theological Seminary. In 1873, Wilson became a communicant member of the Columbia First Presbyterian Church; he remained a member throughout his life.