In 1834, the city of Rio de Janeiro was elevated to Imperial capital of the Empire of Brazil, and was included in the Neutral Municipality (Portuguese: Município Neutro).

When Brazil became a republic in 1889, the city of Rio de Janeiro remained the national capital, and the territory of the Neutral Municipality became the Federal District (Portuguese: Distrito Federal), while the surrounding homonymous province became a state, still with Niterói as its capital.

In 1960 the Fourth Brazilian Republic moved the national capital to Brasília and a new Federal District was created for it.

On the other hand, that also meant that the Guanabara state government had some functions that were normally assigned to municipalities elsewhere, such as regulating urban zoning, inspecting the safety of buildings, or issuing licenses for commercial venues, for example.

In gubernatorial elections held on 3 October 1965, Francisco Negrão de Lima [pt], a candidate supported by a coalition formed by PTB and PSD and a close associate of former President Juscelino Kubitschek, won the race to be the state's governor, garnering 52% of the votes cast.