The Second Nicaraguan Campaign (1926–1933) was a U.S. military intervention aimed at stabilizing Nicaragua during a period of civil war and political unrest. American forces were deployed to protect U.S. interests, support the Nicaraguan government, and oversee elections, but they soon became engaged in a prolonged counterinsurgency campaign against rebel leader Augusto César Sandino. U.S. Marines conducted patrols, security operations, and combat missions in difficult terrain while also helping to establish and train the Nicaraguan National Guard. The conflict became a notable example of early 20th-century U.S. involvement in Latin America and influenced later military doctrine on small wars and counterinsurgency operations.