Theodore Roosevelt

Roosevelt led the Rough Riders, a volunteer cavalry unit, in the Battle of San Juan Hill during the Spanish-American War. The victory made him a national hero and boosted his political career.

Roosevelt's administration sued the Northern Securities Company, a railroad monopoly, under the Sherman Antitrust Act. The Supreme Court ordered its dissolution, establishing Roosevelt's reputation as a trust-buster.

Roosevelt supported and oversaw the construction of the Panama Canal, which connected the Atlantic and Pacific Oceans. The US supported Panama's independence from Colombia to secure the canal zone, and the canal opened in 1914.

Roosevelt announced the Roosevelt Corollary, asserting the US right to intervene in Latin American nations to stabilize their economies and prevent European intervention. This expanded US influence in the Western Hemisphere.

Roosevelt established the US Forest Service and designated 150 million acres of national forests. He also created five national parks and 18 national monuments, significantly expanding federal land conservation.