Udall, Stewart Lee (yōˈdôl) [key], 1920–2010, U.S. cabinet member and environmentalist, b. St. Johns, Ariz. After serving in World War II, Udall practiced law in Tucson until elected to the U.S. House of Representatives in 1954. As a member of the Committee on Interior and Insular Affairs he gained a reputation as a conservationist and an advocate of public works. An early supporter of John F. Kennedy for the presidency, he became in Jan., 1961, the first Arizonan to hold a cabinet post. As secretary of the interior under both Kennedy and Lyndon B. Johnson, he stressed government dam building to generate increased public power, presided over a vast enlargement of the national park system, and promoted laws protecting clean air and water, increasing land conservation, and preserving historic sites. He subsequently wrote a syndicated newspaper column, taught at Yale, and resumed his law practice. Udall wrote National Parks of America (1966), The Quiet Crisis (1963, repr. 1967), 1976: Agenda for Tomorrow (1968), and The Myths of August (1994). His younger brother, Morris King "Mo" Udall, 1922–98, succeeded him in Congress (1961–91). His son Thomas Udall, 1948–, was first elected to the U.S. House of Representatives from New Mexico in 1998 and has been a U.S. senator since 2009. Mo Udall's son Mark Udall, 1950–, was also first elected to the House of Representatives, from Colorado, in 1998 and has been a U.S. senator since 2009.