- The US purchased the Louisiana Territory from France for $15 million, greatly expanding the country's western lands and opening the way for westward expansion.
Florida Purchase (1819):
- The US acquired Florida from Spain for $5 million, securing control of the Florida Peninsula and resolving border conflicts between the US and Spain.
Mexican-American War (1846-1848):
- The US defeated Mexico in the Mexican-American War, resulting in the Treaty of Guadalupe Hidalgo, which ceded control of vast territories to the US, including present-day California, Nevada, Utah, New Mexico, and parts of Arizona and Colorado.
Gadsden Purchase (1853):
- The US purchased additional land from Mexico, known as the Gadsden Purchase, primarily to facilitate the construction of a transcontinental railroad.
Spanish-American War (1898):
- As a result of the Spanish-American War, Spain relinquished control of Cuba, Guam, Puerto Rico, and the Philippines to the US.