On July 1, 1974, Brazil enacted legislation merging the State of Guanabara with the State of Rio de Janeiro. Guanabara had existed as a separate state since 1960, when Rio de Janeiro lost its status as the national capital. The merger aimed to improve administrative efficiency and regional coordination. It eliminated Guanabara as a federative unit and expanded Rio de Janeiro state’s jurisdiction. The decision occurred during Brazil’s military dictatorship under President Ernesto Geisel.
