Sarah Brady, a longtime champion of gun control and the widow of former White House Press Secretary James Brady, died Friday of pneumonia at the age of 73, according to a statement released by her family.

Brady became a prominent voice for stricter gun legislation after her husband was critically injured in an assassination attempt on President Ronald Reagan in 1981. Reagan recovered from the attack, while James Brady, who was press secretary at the time, was shot in the head and left with partial paralysis that kept him in a wheelchair for the remainder of his life. He died in August 2014.

The gunman, John Hinckley Jr., was found not guilty by reason of insanity and remains in a mental institution today.

Sarah Brady lobbied for the Brady Handgun Violence Prevention Act, which required background checks for firearms purchases and a five-day waiting period. The bill was signed into law by President Bill Clinton in 1993.

She also was the chair of the Brady Campaign and Center to Prevent Gun Violence, which released a statement Friday on her death. “Our nation has lost a great hero, and I have lost a dear friend,” said Dan Gross, president of the center, in the statement. “I am certain that she would want nothing more than to know we are carrying on her and Jim’s legacy with the same fiery compassion and dedication that made her so remarkable.”

Gross also called the Brady Handgun Violence Prevention Act the “most significant achievement in the history of the gun violence prevention movement.”

U.S. Sen. Charles Schumer, author of the Brady Bill, said in a statement: "Sarah Brady took the tragedy of her husband’s shooting and turned it into a movement that saved tens of thousands of lives.  She was strong and forceful, sweet and kind, and someone I considered a friend and patriot for decades. She was a true hero and will be missed by America."

The National Rifle Association also issued a statement Friday honoring Brady. “Although we disagreed on public policy, Sarah Brady was an honorable American who we always respected,” the organization said.