THEODORE ROOSEVELT (1858-1919) Roosevelt’s service in the Navy Department and in the war against Spain brought out his aggressive qualities. He believed at the time that power was necessary for a country to achieve greatness, and that war was a test of superiority. He also believed that civilized nations had a right to interfere in the affairs of less advanced nations in order to improve the civilization of all. Soon after the Spanish-American War broke out tin 1898, Roosevelt helped to organize the First United States Volunteer Cavalry Regiment better known as the Rough Riders. He took command of the regiment in Cuba, and on July first he led an asult on a hill outside