John Joseph "Black Jack" Pershing, GCB (Hon) (September 13, 1860 – July 15, 1948), was a general officer in the United States Army who led the American Expeditionary Forces in World War I. Pershing is the only person to be promoted in his own lifetime to the highest rank ever held in the United States Army—General of the Armies (a retroactive Congressional edict passed in 1976 promoted George Washington to the same rank but with higher seniority). Pershing holds the first United States officer service number (O-1). He was regarded as a mentor by the generation of American generals who led the United States Army in Europe during World War II, including George C. Marshall, Dwight D. Eisenhower, Omar N. Bradley, and George S. Patton.

John Joseph Pershing was born on a farm near Laclede, Missouri, to businessman John Fletcher Pershing and homemaker Ann Elizabeth Thompson. He also had five siblings: brothers James (b.1862) and Ward (b.1874), and sisters Mary Elizabeth (b.1864), Anna May (b.1867) and Grace (b.1869); three other children died in infancy. When the Civil War began, his father worked as a sutler for the 18th Missouri Volunteer Infantry, but did not serve in the military.

World War I (WWI), which was predominantly called the World War or the Great War from its occurrence until 1939 (World War II), and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918. It involved all the world's great powers, which were assembled in two opposing alliances: the Allies (based on the Triple Entente of the United Kingdom, France and Russia) and the Central Powers (originally centred around the Triple Alliance of Germany, Austria-Hungary and Italy; but, as Austria–Hungary had taken the offensive against the agreement, Italy did not enter into the war). These alliances both reorganised (Italy fought for the Allies), and expanded as more nations entered the war. Ultimately more than 70 million military personnel, including 60 million Europeans, were mobilised in one of the largest wars in history. More than 9 million combatants were killed, largely because of enormous increases in lethality of weapons, thanks to new technology, without corresponding improvements in protection or mobility. It was the sixth-deadliest conflict in world history, subsequently paving the way for various political changes such as revolutions in the nations involved.

Thomas Woodrow Wilson (December 28, 1856 – February 3, 1924) was the 28th President of the United States, from 1913 to 1921. A leader of the Progressive Movement, he served as President of Princeton University from 1902 to 1910, and then as the Governor of New Jersey from 1911 to 1913. Running against Progressive ("Bull Moose") Party candidate Theodore Roosevelt and Republican candidate William Howard Taft, Wilson was elected President as a Democrat in 1912.

In his first term as President, Wilson persuaded a Democratic Congress to pass major progressive reforms. Historian John M. Cooper argues that, in his first term, Wilson successfully pushed a legislative agenda that few presidents have equaled, and remained unmatched up until the New Deal. This agenda included the Federal Reserve Act, Federal Trade Commission Act, the Clayton Antitrust Act, the Federal Farm Loan Act and an income tax. Child labor was curtailed by the Keating–Owen Act of 1916, but the U.S. Supreme Court declared it unconstitutional in 1918. He also had Congress pass the Adamson Act, which imposed an 8-hour workday for railroads. Wilson, after first sidestepping the issue, became a major advocate for the women's suffrage.