The United States occupied Nicaragua from 1909 to 1933 and intervened in the country several times before that. The American interventions in Nicaragua were designed to prevent the construction of a trans-isthmian canal by any nation but the USA. Nicaragua assumed a quasi-protectorate status under the 1916 Chamorro-Bryan Treaty. The occupation ended as Augusto César Sandino, a Nicaraguan revolutionary, led guerrilla armies against US troops. Furthermore, the onset of the Great Depression made it costly for the USA to maintain occupation.