President Joe Biden on Saturday signed into law the gun safety package passed by Congress this week.
"Time is of the essence," Biden said as he delivered remarks in the Roosevelt Room alongside first lady Jill Biden. "Lives will be saved."
The Bipartisan Safer Communities Act broke a nearly 30-year stalemate on Capitol Hill, becoming the first major piece of federal gun reform to clear both chambers since the Brady bill.
"At a time when it seems impossible to get anything done in Washington, we are doing something consequential," Biden said.
A bipartisan group of senators began crafting the legislation in the aftermath of a tragic mass shooting at Robb Elementary School in Uvalde, Texas, that left 19 young children and two teachers dead.
In heartbreaking testimony, lawmakers heard directly from a fourth grader trapped inside her classroom as the rampage unfolded. She testified that she smeared herself with her classmate's blood and played dead to survive as the shooter terrorized the school for more than an hour.
The House passed the Senate-backed legislation on Friday -- exactly one month after the Uvalde massacre.
Following the historic vote, House Speaker Nancy Pelosi held a bill enrollment ceremony where she said Congress was "honoring a promise in honor of all those who have lost loved ones to gun violence."
The law includes $750 million to help states implement "red flag" laws to remove firearms from people deemed to be a danger to themselves or others, as well as other violence prevention programs. It also provides funding for a variety of programs aimed at shoring up the nation's mental health apparatus and securing schools.
It will enhance background checks for gun buyers under the age of 21 by giving authorities up to 10 business days to review the juvenile and mental health records of young gun purchasers, and makes it unlawful for someone to purchase a gun for someone who would fail a background check.
Another key provision is closing the so-called "boyfriend loophole" so individuals in "serious" "dating relationships" who are convicted of domestic abuse will be prevented from purchasing a gun.
But the law doesn't go as far as Democrats -- and Biden -- wanted, excluding measures such as universal background checks and a ban on assault weapons and high-capacity magazines.
The House has passed several bills with stricter gun regulations, but none have been taken up in the Senate.
"I know there's much more work to do, and I'm never going to give up," Biden said on Saturday. "But this is a monumental day."
The signing of the gun safety bill comes just days after a major Supreme Court decision expanding gun rights.
The court's conservative majority struck down a 100-year-old New York law that restricted the concealed carry of handguns in public to only those with a "proper cause." Justice Clarence Thomas wrote in the opinion that the Second and Fourteenth Amendments protect an individual's right to carry a handgun for self-defense outside the home.
The high court on Friday also delivered a ruling overturning Roe v. Wade, the landmark decision legalizing abortion access nationwide for the past 50 years.
When asked about the Supreme Court on Saturday, Biden said he thought the court has "made some terrible decisions."