Elihu Root (February 15, 1845 – February 7, 1937) was an American lawyer, Republican politician, and statesman who served as the 41st United States Secretary of War under presidents William McKinley and Theodore Roosevelt and the 38th United States Secretary of State, also under Roosevelt. In both positions as well as a long legal career, he pioneered the American practice of international law. Root is sometimes considered the prototype of the 20th-century political "wise man", advising presidents on a range of foreign and domestic issues. He also served as a United States Senator from New York and received the 1912 Nobel Peace Prize.
Root was a leading New York City lawyer who moved frequently between high-level appointed government positions in Washington, D.C., and private-sector legal practice in New York. He headed organizations such as the Carnegie Endowment for International Peace and the American Society of International Law.
As Secretary of War from 1899 to 1904, Root administered colonial possessions won in the Spanish–American War. Root favored a paternalistic approach to colonial administration, emphasizing technology, engineering, and disinterested public service.