John Philip Sousa (1854–1932) directed the United States Marine Band from 1880 to 1892 and then founded the Sousa Band, the most popular concert ensemble in the world from 1892 to roughly 1925. He wrote 136 marches. Five — Stars and Stripes Forever (1896), The Washington Post March (1889), Liberty Bell March (1893), Semper Fidelis (1888), and The Thunderer (1889) — are the definitive examples of the form. Stars and Stripes Forever was designated the national march of the United States by an act of Congress signed in December 1987. Sousa's place in the march tradition is roughly the place Beethoven holds in the symphony: not the inventor, but the figure whose work fixed the genre's canonical shape.
The march as a musical form descends from European military music — the Ottoman janissary bands' brass-and-percussion ensembles that traveled with Suleyman's army impressed European observers from the sixteenth century, and Frederick the Great's Prussian drill regulations of the 1740s codified marching tempo (Quick Step at ~120 bpm) and the function of music as drill regulator. The American Civil War mass-produced brass bands on both sides; after the war the surplus instruments and trained players seeded the town band tradition, and the United States Marine Band — the President's Own, founded 1798 — became the country's flagship ensemble. Sousa form (the canonical American march structure) follows a fixed arc: introduction (often a four-bar fanfare), first strain (in the home key, repeated), second strain (frequently more contrapuntal, repeated), trio (in the subdominant key, lyrical, often quieter), break strain (loud, contrapuntal, the dramatic centre), trio reprise with grandioso (the famous piccolo countermelody in Sousa's most-played march is the textbook example). Meter is almost always 2/4 (the military quickstep) or 6/8 (the quickstep in compound meter). Instrumentation centres on brass and percussion with woodwind colour; piccolo and snare drum are the two voices most identified with the form. Adjacent traditions: the Strauss family's Radetzky March (1848) extended the form into Viennese ballroom music; Edward Elgar's Pomp and Circumstance Marches (1901–1930) — especially No. 1, the source of Land of Hope and Glory — became the British equivalent of Sousa; Tchaikovsky's 1812 Overture incorporates an explicit military-march vocabulary. Karl King, Henry Fillmore, and Edwin Franko Goldman continued the American march tradition into the mid-twentieth century.
Sousa marches remain the core repertoire for marching bands, military bands, concert bands, and July 4th / Memorial Day civic programmes. The Sousa Band itself was dissolved on the composer's death in 1932, but the United States Marine Band he once led performs his repertoire continuously. The wind ensemble tradition — formally separated from the marching tradition by Frederick Fennell at the Eastman School in 1952 — descends directly from Sousa's concert-band model and is the most-active form of large-ensemble Western art music in twenty-first-century North American schools and universities. The Liberty Bell March (1893) became globally familiar as the opening theme of Monty Python's Flying Circus (1969). And the marching band itself — high-school and college bands, drum and bugle corps, college-football halftime productions — is the most-visible Western large-ensemble tradition in 2020s American public life.