On the eve of his 100th day in office, President Trump rallied a convention of the National Rifle Association by vowing to "never, ever infringe" on Second Amendment rights and declaring his predecessor's alleged "assault" on those freedoms is over.

“I am here to deliver you good news: the eight-year assault on your Second Amendment freedoms has come to a crashing end,” Trump told the cheering crowd.

Trump is the first sitting president to address an NRA convention in more than three decades. The last president to do so was Ronald Reagan in 1983.

Trump started his address with a freewheeling recollection of his November election victory, crediting the gun rights group for helping him win. "You came through for me and I am going to come through for you," he said.

The NRA endorsed Trump after he promised to do away with then-President Barack Obama’s efforts to strengthen background checks. Trump himself was a onetime support of gun control before he entered politics. During the presidential race, he became a champion of gun rights and often spoke about his Democratic rival Hillary Clinton’s intent to abolish the Second Amendment – a claim she never made.

The NRA spent more than $30 million to help Trump get elected.

“I will never, ever infringe on the rights of the people to keep and bear arms,” Trump told the crowd.

The president’s speech touched on familiar themes – his vow to root out radical Islamic terrorists and build a border wall with Mexico.

“You need that wall to stop human trafficking,” Trump said. “We’ll build the wall, don’t even think about it. We need the wall.”

Ahead of Trump’s appearance, the chief lobbyist for the NRA told the group’s convention that on Election Day, “our candidate became our president.”

Chris Cox received repeated ovations as he addressed the NRA's 146th annual meeting. Cox named some of the key appointees in the Trump administration, including newly installed Supreme Court justice Neil Gorsuch, Attorney General Jeff Sessions and Defense Secretary Jim Mattis.

The applause was interspersed with boos when he mentioned Clinton and Obama.

Cox said, "The men and women of the [NRA] haven't backed down from a fight in 146 years, and we sure as hell weren't scared of Hillary Clinton."

As the president addressed pro-gun members of the NRA, advocates pushing for stricter gun control measures gathered in downtown Atlanta to protest the president’s appearance. They carried signs supporting background checks and even held a “die-in,” lying down to symbolize victims of gun violence before marching toward the Georgia World Congress Center where the NRA is holding its weekend-long conference.

While Trump is in town, he’ll also attend a private fundraiser for Karen Handel, the Republican congressional candidate in a tough runoff race against Democratic rival Jon Ossoff to fill now-Health and Human Services Secretary Tom Price’s House seat.

Ossoff finished a crowded 18-person special election earlier this month with 48 percent of the vote. He needed 50 percent of the vote to win the election outright. The runoff is scheduled for June 20.