United States Senator and member of the Democratic Party who represented Wyoming from 1959 until 1977. He was the 9th United States Ambassador to the Organization of American States under President Jimmy Carter.
He worked as a high school teacher while studying for a master's degree in history from the University of Colorado.
As of 2014, he is the last Democrat to have been elected to a Senate seat from Wyoming.
He married Loraine Baker in 1939 and together they had four children.
He was good friends with President John F. Kennedy.