He was an army officer during the Chaco War and subsequently became Minister of War. When President José Félix Estigarribia was killed in an air crash (1940), Morínigo became President (1940–48). He suspended the constitution and established a harsh military dictatorship. Housing and public health were improved during his tenure, and, in 1946, political exiles were brought into a more democratic cabinet. When these were ousted on suspicion of treason (1947), civil war broke out and a broadly based opposition, led by the Colorado Party, forced his retirement and exile to Argentina (1948).