He often won re-election by some of the largest majorities of any congressman. He was a member of the House Ways and Means Committee for much of his congressional career. A staunch conservative, he supported U.S. involvement in the Vietnam War, and advocated tougher policies against antiwar demonstrators. Duncan voted against the Voting Rights Act of 1965 but in favor of the Civil Rights Act of 1968. He was one of the first congressmen to endorse Richard Nixon for president in 1967. In the late 1970s, Duncan engaged in a protracted legislative struggle with environmentalists over the Tennessee Valley Authority's construction of Tellico Dam, on the Little Tennessee River, in Duncan's district. The dam's completion had been halted over concerns for the endangered snail darter, which lived in the river. After numerous failed attempts to amend the Endangered Species Act to allow the dam's completion, Duncan managed to insert a rider into the Energy and Water Development Appropriations Act in July 1979, on a day when most House members were absent. The dam's opponents cried foul, but the bill nevertheless passed the Senate and was signed into law, allowing TVA to finally close the dam's gates. Duncan served in the House until his death from cancer in 1988. Personal life Duncan married Lois Swisher of Iowa City, Iowa in 1942. They had four children, including John J. "Jimmy" Duncan Jr., who won his father's former congressional seat in the special election that followed his father's death. See also List of United States Congress members who died in office (1950–99) References External links John J. Duncan Sr. Papers, University of Tennessee Knoxville Libraries 1919 births 1988 deaths 20th-century American politicians 20th-century American lawyers Tennessee lawyers Mayors of Knoxville, Tennessee People from Scott County, Tennessee Cumberland University alumni Republican Party members of the United States House of Representatives from Tennessee Deaths from cancer in Tennessee Deaths from prostate cancer United States Army personnel of World War II United States Army non-commissioned officers University of Tennessee alumni