When Brazil's capital was transferred from the city of Rio de Janeiro to Brasília in 1960, the old municipal region that had included the capital of colonial Brazil (1763–1808), the seat of the Portuguese crown (1808–1822), the Brazilian Empire (1822–1889), and the capital of the Federal Republic (1889–1960) became the nation's smallest state and was given the name Guanabara. The creation of Guanabara State, and the transfer of the capital had been determined by the constitutions of 1891, 1934, and 1946.
Soon after these measures were implemented, however, it became clear that both Guanabara State and neighboring Rio de Janeiro were at a political and economic disadvantage compared with the bigger, more economically diverse Minas Gerais and São Paulo. Lack of capital and infrastructure in Rio de Janeiro and of natural resources in Guanabara, which depended upon its neighbor for water and electricity, together with the migration of urban industries from Guanabara to Rio de Janeiro, convinced most of the politicians of both states, including their two governors, that there should be a merger. In 1975 the national Congress decided that the two states would join, and named the new state Rio de Janeiro. The area that had been Guanabara State became the municipal district of Rio de Janeiro.
Fatos e Fotos, May 2, 1967, pp. 14-16; Feb. 12, 1970, pp. 4-7; June 10, 1974, pp. 14-17; Grande enciclopedia Larousse (1978).
Dulles, John F. Carlos Lacerda, Brazilian Crusader. Austin: University of Texas Press, 1991–1996.
Motta, Marly Silva da. Saudades da Guanabara. Rio de Janeiro: Editora FGV, 2000.