Theodore Roosevelt

Theodore Roosevelt Jr. was the 26th president of the United States, serving from 1901 to 1909. The 25th vice president, he assumed the presidency after the assassination of William McKinley. Roosevelt was a progressive Republican who founded the Bull Moose Party after William Howard Taft defeated him in the 1912 Republican presidential primaries. He was the youngest person to be president, aged 42 upon his first inauguration.
A sickly child with debilitating asthma, Roosevelt overcame health problems through a regime of vigorous exercise, which he called "the strenuous life". He was homeschooled and began a lifelong naturalist avocation before attending Harvard University. His book The Naval War of 1812 established his reputation as a historian and popular writer. Roosevelt became leader of the reform faction of Republicans in the New York State Legislature. After the simultaneous deaths of his first wife Alice Hathaway Lee Roosevelt and mother Martha Bulloch Roosevelt, he recuperated by buying and operating a cattle ranch in the Dakotas. Roosevelt served as the assistant secretary of the Navy under McKinley, and in 1898 helped plan the successful naval war against Spain.