How did the United States turn into a great power?

CAIRO – 28 February 2022: Today marks the 125th anniversary of Britain's recognition of US authority over the Western Hemisphere, on February 28, 1897.

During this era, the United States emerged as an active major power even outside its traditional Western Hemisphere area of interest.

But what are the events that transformed the United States from a country that had just emerged from a grinding civil war and severe political conditions, to become a great power in the world competing with Great Britain and the Russian Empire?

Cuba's War of Independence from Spain broke out in 1895. Many Americans demanded American intervention in the war to stop Spanish cruelty. 

The business community and top Republican Party leaders have curbed their desire to intervene, but the issue took on a high priority with the explosion and sinking of the USS Maine (1889) in Havana harbor during a peacekeeping mission. McKinley demanded that Spain ease its control of Cuba, but Madrid rejected these demands.

McKinley took the issue to Congress, which in turn declared war on Spain in April of 1898. The United States quickly defeated Spain in the Spanish-American War, and gained control of Spanish possessions in Cuba, Puerto Rico, and the Philippines.

Cuba became an American protectorate in the aftermath of the de facto war, and the United States put down the Philippine insurgency (Philippine-American War).

McKinley was unable to obtain a two-thirds majority to ratify the Hawaii annexation treaty due to opposition from Senate Democrats, but he achieved this result by a majority vote on the Newlands Resolution in 1898. This decision resulted in the establishment of a major strategic base in the Pacific Ocean. Thus, the McKinley administration established the first overseas American colonialism in American history.

Determined to continue expanding the influence of the United States, President Roosevelt emphasized modernizing the small army and greatly expanding the massive US Navy.

Roosevelt presided over a rapprochement with Britain, after which he issued the Roosevelt Corollary, which stipulated the intervention of the United States in the financial affairs of the unstable countries of the Caribbean and Central America in order to thwart direct European interference in them.

The United States of America was involved in a series of interventions in Latin America known as the Banana Wars as a partial result of Roosevelt Corollary. 

Roosevelt supported the secession of Panama, and later signed a treaty with it to create the Panama Canal Zone, after Colombia rejected a treaty giving the United States a lease across the Isthmus of Panama.

The Panama Canal was completed in 1914, greatly reducing transportation time between the Atlantic and Pacific Oceans. Roosevelt's well-publicized work is widely praised.

President Taft acted calmly, pursuing a policy of "dollar diplomacy", focusing on the use of US financial power in Asia and Latin America. Taft did not have much success.