On July 25, 1898, General Nelson A. Miles led the US attack and landed armed forces in Guánica Bay during the Spanish-American War. After several battles against Spanish troops and a subsequent ceasefire on December 10, 1898, Spain ceded sovereignty over Puerto Rico to the US through the Treaty of Paris. The US began to emerge as a new empire, acquiring colonies in the Caribbean and Pacific. US companies exploited these colonies for profit, dominating international markets, particularly in sugar prices.
Following the invasion, Puerto Rico was administered by a military government, with governors appointed by the US president. From October 1898 to April 30, 1900, the military government controlled politics, economy, and society. Generals Nelson A. Miles, Guy V. Henry, and John R.
Brooke served as leaders and governors. The military suppressed the previous Autonomic Charter, replaced the Puerto Rican peso with the US dollar, and laid the groundwork for a future transition to a civil government. On May 1, 1900, the US Congress approved the Foraker Act, establishing a civil government in Puerto Rico and ending military rule. However, the post-war period was marked by poverty and inflation, and in 1899, Puerto Rico was hit by Hurricane San Ciriaco, which caused over 3,000 deaths, comparable to the damage caused by Hurricane Maria in 2017.