The 1940 Constitution of Cuba was implemented during the presidency of Federico Laredo Brú and took effect on October 10, 1940. It was primarily influenced by the collectivist ideas that inspired the Cuban Revolution of 1933. Widely considered one of the most progressive constitutions at the time, it provided for land reform, public education, a minimum wage and other social programs. It had 286 articles in 19 sections.
Despite the fact that some political parties had refused to participate in some elections in anticipation of fraud by the government in power, all parties presented candidates for the election of a Constitutional Assembly in November 1939. Beneath the variety of parties, the two national leaders who had dominated Cuban politics since the ouster of Machado in 1933: former President Ramón Grau and Fulgencio Batista, a military leader who had dominated several recent presidents. Each maneuvered to form coalitions, but public interest was only sufficient to produce a turnout of 57% of the eligible voters. The 76 delegates from nine political parties first elected Grau chairman, but he was removed when the Conservative Party delegates, who had campaigned in opposition to Batista, switched sides and supported Batista's candidate for chairman, Carlos Márquez Sterling. The assembly debated publicly for six months and adopted the constitution at the Capitol in Havana. It was signed on July 1, 1940, in Guáimaro, Camagüey, as a tribute to the anti-colonial revolutionaries who signed a draft of a proposed Cuban constitution there in 1879. A later U.S. Ambassador to Cuba, Philip Bonsal assessed the outcome:
Even before attaining its independence from Spain, Cuba had several constitutions either proposed or adopted by insurgents as governing documents for territory they controlled during their war against Spain. Cuba has had several constitutions since winning its independence. The current constitution was drafted in 1976 and has since been amended.
Events in early nineteenth-century Spain prompted a general concern with constitutions throughout Spain's overseas possessions. In 1808, both King Ferdinand VII and his predecessor and father, Charles IV, resigned their claims to the throne in favor of Napoleon Bonaparte, who in turn passed the crown to his brother Joseph. In the ensuing Peninsular War, the Spanish waged a war of independence against the French Empire. On 19 March 1812, the Cortes Generales in refuge in Cádiz adopted the Spanish Constitution of 1812, which established a constitutional monarchy and eliminated many basic institutions that privileged some groups over others. The Cortes included representatives from throughout the Spanish Empire, including Cuba.