Correction: An earlier version of this editorial incorrectly stated that Rep. Frank Wolf’s retirement would come after 32 years in the House. Presuming that Mr. Wolf completes his current term, it would actually come after 34 years in the House.

IN A Republican Party that attaches little value to mavericks and independent voices, Rep. Frank Wolf has stood apart for years. His decision to retire after 34 years representing Northern Virginia in Congress, announced Tuesday, marks the departure of a principled public servant whom many regarded as a conscience of the House of Representatives.

Elected in the Reagan revolution of 1980, Mr. Wolf has been a steadfast advocate for many conservative causes. He has opposed abortion, same-sex marriage, adoptions by gay couples and many gun-control measures. Yet he also retained a courageous knack for challenging GOP orthodoxy and setting his own political compass.

One of just a handful of House Republicans who refused to sign Grover Norquist’s pledge never to raise taxes, he took the House floor to attack Mr. Norquist’s purity tests. Having pushed to establish a bipartisan commission on the deficit, he broke ranks with his party to endorse the commission’s main recommendation — a balanced approach that included increasing revenue and cutting spending.

Behind the headline issues, few lawmakers in Congress worked local issues as hard or persistently as Mr. Wolf, or could claim as many big and tangible achievements. That was especially true on transportation projects that are critical to his district, which includes parts of Fairfax, Prince William and Loudoun counties. From his position on the transportation subcommittee of the House Appropriations Committee, Mr. Wolf was instrumental in rallying support and funding for renovations to Dulles and Reagan National airports, reconstruction of the Woodrow Wilson Bridge, Metro’s soon-to-open Silver Line to Dulles and the construction and widening of Interstate 66.

Low-key, hard-working, detail-oriented, deeply religious and lacking the spotlight-hogging loquacity of many of his colleagues, Mr. Wolf has been relatively content to let others dominate center stage. Yet it’s no accident that he has not had a serious challenge for reelection in three decades, even though he represents what often has been, and is now, a swing district. His serious, sustained attention to policy, legislation and constituent services earned him broad bipartisan respect.

So did his unstinting advocacy for human rights and oppressed minorities in dangerous and unlovely corners of the world that most members of Congress were content to ignore. In service of those principles, Mr. Wolf slipped into Tibet amid a group of trekkers to investigate the Chinese government’s abuse of Buddhist monks, nuns and others. He led the first congressional delegation to Darfur and returned repeatedly to Sudan to call attention to the mass killing there. His visits to Iraq, Afghanistan, Chechnya and other hot spots reflected his zeal for justice and his conviction that the United States should be a champion for decency and democracy.

As we noted over the years, those qualities have made Mr. Wolf a standout among a sharply diminishing breed of legislators in Congress whose independce and pragmatic problem-solving outweighed their partisanship. In the end, that is the real test of leadership, and Mr. Wolf has met it.