McCarthy had one of the more stunning reasons to run for Congress. Her husband and son were shot in the 1993 Long Island Railroad shooting, in which a gunman boarded a Long Island Railroad train with a handgun, killing six people and injuring 19.

Her son survived with severe injuries that disabled him on one side of his body. Her husband died.

The shooting inspired McCarthy to run for Congress on a gun-control platform as a Democrat despite being a registered Republican. She would remain a Republican until 2003, well into her congressional term in Long Island’s Fourth Congressional District from 1997 to 2015.

Her congressional opponents often bashed her as a one-issue candidate. McCarthy seemed to embrace the attacks.

“Everyone that ever ran against me always said, ‘She’s only a one-issue candidate,’” she told the New York Times in 2014. “I said, ‘Yeah, but at least I’ve got an issue.’ And by the way, I’m a woman. There’s no such thing as a woman having one issue.”

Much of McCarthy’s career was spent struggling with a Republican-controlled Congress that was not apt to pass gun-control measures. Her attempts to renew the 1994 federal ban on assault-style weapons when it expired in 2004 failed. The failures, she admitted, got her down, but those close to her say she never gave up.

“She didn’t accept the result,” former Republican Long Island Rep. Peter King said, “but she accepted the fact that it was going to be a long, hard fight.”

Her most notable success was a piece of legislation she sponsored that was signed into law by former President George W. Bush in 2008 to improve background checks on potentially ineligible gun buyers, such as felons and people with mental illness.

Her congressional legacy also included fighting for abortion rights, opposing the death penalty, and voting for the war in Iraq, as well as former President Bill Clinton’s impeachment investigation.

McCarthy said she would not run for reelection to the House in 2014, citing her health.

Former President Joe Biden awarded her the Presidential Citizens Medal in January 2025.

Several high-profile politicians mourned her death. “After her husband was murdered and her son was shot in the 1993 Long Island Rail Road massacre, Carolyn turned her pain into action,” former Rep. Gabrielle Giffords, who was shot in 2011 and has continued to advocate gun control, wrote on X. “I’m grateful for her courage and all the progress she championed. May her work live on as we continue the fight to build a future free from gun violence.”

Gov. Kathy Hochul (D-NY) called her “kind, principled, and strong.” Rep. Laura Gillen (D-NY), who now represents McCarthy’s district, said, “We must honor her legacy by continuing her life’s work to keep our communities and our children safe from the scourge of gun violence.”

BIDEN AUTOPEN USE: WHAT TO KNOW AS TRUMP ORDERS AN INVESTIGATION INTO HIS PREDECESSOR

Long Island Rep. Tom Suozzi (D), who represents the neighboring Third District, wrote, “I first met Carolyn in early 1994, when I was the young mayor of Glen Cove, and her son, Kevin, was undergoing rehabilitation at Glen Cove Hospital. I followed her closely from her entry into politics and throughout her years in office,” he wrote in a post on X.

“Our nation and our Island have lost a fierce champion,” he said.