Theodore Roosevelt became president in 1901 after the assassination of William McKinley, whose vice-president he had been. He served until 1909.
Roosevelt was called a "trust-buster" and proudly wore the moniker, promoting himself as a heroic smasher of corporate monopolies. He clashed with Big Business, bullying it with regulators and antitrust law. New regulatory bodies took shape under his presidency; reforms such as child-labour restrictions and workplace-safety measures gained ground. The civil service expanded and became more professional. As the writer H.L. Mencken quipped, Roosevelt "didn't believe in democracy; he believed simply in government."
During the 1907 financial crisis, Roosevelt fell silent about the "malefactors of great wealth" he had attacked weeks earlier and let J.P. Morgan's US Steel swallow a financially distressed rival.
Motivated in part by a belief in the natural superiority of the Anglo-Saxon man, Roosevelt sent American troops overseas to expand America's influence. His reasoning became known as the "Roosevelt Corollary" to the Monroe Doctrine: that America may be forced to exercise "an international police power". He quadrupled spending on the navy, turning it into a modern force to support an empire. He fomented a rebellion in Panama against Colombian rule to take control of the nascent canal project.
His flair for diplomacy won him a Nobel peace prize for mediating an end to the Russo-Japanese war of 1905. Rarely in all this did he bother to ask Congress for permission.
Before his presidency, Roosevelt was made a hero by the Spanish-American War of 1898. He led the Rough Riders, a cavalry unit made up of cattle ranchers, coppers and polo players, which helped drive Spain out of Cuba and Puerto Rico within months.
"It would seem that you have no useful skill or talent whatsoever," he said. "Have you thought of going into teaching?"