Humberto de Alencar Castelo Branco's election as president came in the wake of the 1964 military coup that overthrew President João Goulart. This coup was rooted in widespread dissatisfaction with Goulart's administration, perceived leftist policies, and attempts to implement land reforms, which alarmed agrarian elites and segments of the military. Following the coup, the country was in a state of uncertainty, leading the National Congress to seek a new leader who could restore order and unify the nation under a more conservative regime.

Castelo Branco, a career military officer, was chosen as a compromise candidate to lead Brazil during this tumultuous period. His presidency, which formally began after his election, focused on curbing inflation, stimulating economic growth, and restoring political stability. Castelo Branco's administration gained support from business interests and the United States, which viewed his leadership as a bulwark against communism in Latin America at the height of the Cold War. His presidency was characterized by initial support but gradually took on a more authoritarian tone with the suspension of political freedoms and the repression of dissent.

The Castelo Branco presidency also laid the groundwork for subsequent military rule in Brazil, as it was the beginning of a two-decade-long military dictatorship that significantly shaped the country’s political landscape. His government set a precedent for a range of policies that would be utilized by later military leaders, including censorship of the press and the use of state violence against political opponents. Despite his initial intentions to foster stability, the long-term consequences of his election included a legacy of human rights abuses and a struggle for democracy that would persist in Brazil for years to come.