(măk'Әdō), 1863–1941, American political leader, U.S. secretary of the treasury (1913–18), b. near Marietta, Ga. The son of a prominent Georgia jurist, McAdoo became a lawyer in Chattanooga, Tenn. After 1892 he practiced in New York City and was president of the Hudson and Manhattan RR Company, which built and operated the railroad tunnels known as the Hudson Tubes. He actively promoted Woodrow Wilson for the presidency in 1912 and was given a cabinet post. In 1914, after the death (1912) of his first wife, he married Eleanor Randolph Wilson, daughter of the president. The Federal Reserve System was begun during McAdoo's administration of the Dept. of the Treasury, and he was its first chairman. He also managed the financing of American participation in World War I and served as director-general of railroads during the period of government operation (1917–19).
After leaving public office, McAdoo returned to law practice in New York City, then moved to Los Angeles. He was prominent as a contender for the Democratic presidential nomination in 1920, and in 1924 the supporters of McAdoo and the adherents of Alfred E. Smith balanced each other and forced the choice of a compromise candidate. In 1928 he was unable to halt Smith's nomination. His California delegation at the convention in 1932 was joined with the Texas delegation in support of John N. Garner. When this bloc of voters was shifted to Franklin Delano Roosevelt, Roosevelt was nominated. McAdoo later served (1933–39) as senator from California. His autobiography, Crowded Years (1931), ends with his resignation from the cabinet.