 After Joaquín Balaguer, Trujillo's figurehead president, was overthrown in 1962 and the Trujillo family was ousted, Imbert was declared a "National Hero" and was promoted to Major General with the special grant of it being "ad vitam" or lifelong.In the Civil War in the Dominican Republic of 1965 he led one of the factions in the struggle which faced the constitutionalist government led by Colonel Francisco Caamaño, who tried to bring back Juan Bosch to the country's presidency.Imbert's faction, called the Government of National Reconstruction was endorsed by the U.S. troops inspectors, in addition, he was one of the collaborators with the Americans, finally signing a peace act that put an end to the April war.