(b. October 27, 1858, d. January 6, 1919) Twenty-fifth president of the United States (1901–1909).

Theodore Roosevelt led the United States into the front ranks of the world's imperial powers at the turn of the twentieth century. He pushed for war with Spain during the 1890s and then served in the Spanish-American War. As president from 1901 to 1909, Roosevelt promoted American overseas interests and modernized U.S. military forces. After World War I erupted in Europe, he argued for American military preparedness and intervention, and hoped to serve his country again on the battlefield.

Roosevelt was born into one of the richest families in New York City. Although asthma and physical frailty plagued him in his youth, he enjoyed a life of privilege. His formal education consisted chiefly of private tutors, studies in Germany, and a degree from Harvard College. Throughout the 1880s and 1890s, he served in various governmental positions, but...