Near the end of his presidency, James Monroe issued a proclamation to Europe called the Monroe Doctrine
The Doctrine warned European powers not to attempt to bring their imperialism to the Western Hemisphere and that the Americas were to be conquered by the United States
The document spurred American leaders into having interest in conquering and acquiring more land
They wanted to guarantee free trade in the region since it would provide a massive economic benefit over trading overseas
The Spanish-American War
The U.S. didn’t emerge as a major imperial power until the brief Spanish-American War ended
The war started when a U.S. battleship named Maine exploded and sank into the Havana harbor in Cuba
Due to many tensions between the nations at the time, U.S. leaders saw the sinking as a sabotage and declared war on Spain
Spain fell to a crushing defeat, losing their fleet at Manila in a single day
The U.S. also decided to conquer Guam and the Philippines to avoid them from falling into German or Japanese hands
As per their defeat, Spain was forced to give Cuba and Puerto Rico up to the U.S.
A battle from the Spanish-American War.
Map showcasing which countries controlled Caribbean territories by the end of the Spanish-American War
The Monroe Doctrine served as a warning to European states, reminding them that the United States was the dominant power in the Western Hemisphere.
Map of the Panama Canal. The canal created a pipeline between the Atlantic and the Pacific, making trade much easier.
Other Land Gains
The U.S. purchased Alaska from the Russians and used it as a colony
They also claimed Hawaii, but existing leadership there prevented them from annexing it
Eventually, planters and businessmen living in Hawaii overthrew Queen Lili'uokalani
Hawaii was later annexed into the U.S., but their economic improvement attempts didn't stop there
The United States supported a Colombian rebellion, and in exchange for their help, they earned the right to build the Panama Canal
The canal heavily strengthened the U.S.' military and economic power since ships could move through much easier