In 1915 President Woodrow Wilson ordered U.S. Marines to occupy Haiti following a coup d’état. Stirred by reports of widespread atrocities related to the American occupation, in March 1920 the NAACP sent James Weldon Johnson to Haiti for six weeks to investigate. Johnson exposed the abuses he found in a series of articles for The Nation, which roused international attention and led to the abatement of the worst excesses. He also briefed Warren G. Harding, the Republican presidential candidate, who used the issue to defeat Democratic candidate James Cox. When Harding became president he ordered a special Senate investigation. The NAACP pressed for the restoration of full Haitian sovereignty. The U.S. finally withdrew from Haiti in 1934.