The U.S. Invasion and Occupation of Haiti (1915–1934) began after political instability and violence threatened American interests and regional security in the Caribbean. U.S. Marines entered Haiti following the assassination of President Vilbrun Guillaume Sam and remained for nearly two decades, overseeing government finances, infrastructure projects, and the creation of the Haitian Gendarmerie. While the occupation brought some modernization efforts, including road construction and administrative reforms, it also faced armed resistance from Haitian rebels known as Cacos and generated long-term resentment over foreign control. The occupation significantly shaped Haiti’s political development and reflected broader U.S. interventionist policies in the early 20th century.