With the death of former U.S. Rep. Lee Hamilton, Indiana and Washington lost a figure long associated with congressional oversight on foreign affairs and national security. Hamilton, an Indiana Democrat who spent decades in the House and later continued work on global policy, died Tuesday at his Bloomington, Indiana home, according to his son Doug Hamilton.

Hamilton was known for a reputation as a moderate lawmaker respected by Democrats and Republicans alike, and he became a central voice on international relations during his years in Congress. The Associated Press described him as a calm, deliberate lawmaker who rose to lead influential House committees, including serving as chairman of the House Foreign Affairs and Intelligence committees and as a Democratic leader on international relations before retiring in 1999.

In the House, Hamilton also took on roles connected to some of the country’s most consequential security investigations. After being selected in 2002 as vice chairman of the Sept. 11 attacks commission, he helped oversee a review that lasted 20 months and examined the 2001 attacks—when 19 hijackers flew airliners into the World Trade Center towers in New York, the Pentagon, and targets in Pennsylvania.

The Sept. 11 commission’s work and its resulting report placed Hamilton at the center of a bipartisan public accounting, including through what the AP described as clashes with the George W. Bush White House over changes the panel sought to the U.S. intelligence system. The commission concluded that both the Clinton and Bush administrations failed to grasp the gravity of terrorist threats and took actions that did not even slow the al-Qaida plotters, and the AP quoted Hamilton saying the country “just didn’t get it” when the commission released its report in 2004.

Before the Sept. 11 commission era, Hamilton gained national prominence in the mid-1980s with his selection as co-chairman of the congressional Iran-Contra committee. That panel investigated the Reagan administration’s diversion of profits from Iran arms sales to support Nicaragua’s Contra rebels, and it concluded that President Ronald Reagan created an atmosphere at the White House that left subordinates feeling free to skirt the law and the Constitution.

At the time the committee issued its report, Hamilton said there was “too much secrecy and deception,” adding that information was withheld from Congress, other officials, friends and allies, and the American people. The Associated Press reported that Hamilton faced limited Republican support for the committee’s work, including from then-Rep. Dick Cheney, a top Republican on the committee, who called the panel’s report a political document that selected only the most damaging evidence against the Reagan administration.

Hamilton also took positions early in his career on major foreign policy debates. The AP reported that he was at the forefront of congressional opposition to the 1991 Persian Gulf War conducted by President George H.W. Bush and that he advocated continued economic sanctions against Iraq before military action followed Iraq’s invasion of Kuwait.

After leaving Congress, Hamilton continued his involvement in foreign affairs and institutional reforms. The AP said he served as director of the Washington-based Woodrow Wilson Center and later taught at Indiana University, which in 2018 named its School of Global and International Studies for Hamilton and longtime Republican Sen. Richard Lugar, who died in 2019.

Tributes came from across the political spectrum after Hamilton’s death. The AP reported that President Barack Obama presented Hamilton with the Presidential Medal of Freedom in 2015, praising him as a man “widely admired” for honesty and wisdom and for a “consistent commitment to bipartisanship.” In statements after the death, Indiana Gov. Mike Braun, a Republican, said Indiana mourned Hamilton and described his life as embodying “integrity, civility, and public service,” and former Vice President Mike Pence said his respect for Hamilton was “boundless.”

Hamilton was 33 when he won election to his southern Indiana congressional seat in 1964, and the AP traced his early profile as a small-town lawyer and high school basketball star. The Associated Press also reported that Hamilton was born April 20, 1931, in Daytona Beach, Florida, and moved with his family to Evansville, Indiana, before going on to study at DePauw University, attend Goethe University in Frankfurt, Germany, and graduate from Indiana University’s law school in 1956. Hamilton was married for 58 years, and the AP reported he is survived by three children, five grandchildren and one great-grandchild.