served six years in Congress as a Democrat from Arizona, and then headed the Interior Department for eight years under Presidents Kennedy and Johnson. His son Tom and nephew Mark also became congressmen, then both were elected to the Senate in 2008.Under Stewart Udall's leadership from 1961 through 1968, the Interior Department aggressively promoted an expansion of public lands and helped win enactment of major environmental laws, including ones to protect endangered species.
Udall helped write several of the most far-reaching pieces of legislation, including the Wilderness Act of 1964, which protects millions of acres from logging, mining and other development.
There's more here... and here and here. He was a gentle man of vision who worked ceaselessly for a better world, rather than for only himself.