Udall was known for enthusiastically promoting environmentalism in his position as Secretary of the Interior.

Following his four years in the Air Force and completing his law degree, Udall was elected to the US House of Representatives, where he served for three terms in the Interior, Education, and Labor committees.

From 1961 to 1969, Udall served as Secretary of the Interior under presidents John F. Kennedy and Lyndon B. Johnson. Under his leadership, the Interior Department aggressively pursued the expansion of federal public lands and the enactment of major environmental legislation. Some key environmental laws such as the Clear Air, Water Quality and Clean Water Restoration Acts and Amendments were enacted during Udall’s time.

Udall was also known for his best-selling book, The Quiet Crisis, which was published in 1963, warning of the conservation crisis of the 60s. The Quiet Crisis, which highlighted the need to protect air, water, wilderness, and wildlife, is credited with creating a consciousness in the country that led to the environmental movement.