After World War I, public opinion in the United States began to run against the occupation. Warren G. Harding, who succeeded Wilson in March 1921, had campaigned against the occupations of both Haiti and the Dominican Republic. In June 1921, United States representatives presented a withdrawal proposal, known as the Harding Plan, which called for Dominican ratification of all acts of the military government, approval of a loan of $2.5 million USD for public works and other expenses, the acceptance of United States officers for the constabulary—now known as the National Guard —and the holding of elections under United States supervision. Popular reaction to the plan was overwhelmingly negative. Moderate Dominican leaders, however, used the plan as the basis for further negotiations that resulted in an agreement between U.S. Secretary of State Charles Evans Hughes and Dominican Ambassador to the United States Francisco J. Peynado on June 30, 1922, allowing for the selection of a provisional president to rule until elections could be organized. Under the supervision of High Commissioner Sumner Welles, Juan Bautista Vicini Burgos assumed the provisional presidency on October 21, 1922. In the presidential election of March 15, 1924, Horacio Vásquez Lajara, an American ally who cooperated with the United States government, handily defeated Peynado. Vásquez's Alliance Party  also won a comfortable majority in both houses of Congress. With his inauguration on July 13, control of the republic returned to Dominican hands.
Question: How many years did these events span?
Answer: 3