Romney addressed the conference in Washington, D.C. through a live video feed from Pennsylvania, where he stopped as part of a six state Midwestern bus tour.
In his speech Romney also touched on social issues as he sought to rally religious conservatives behind him.
Romney told the audience that he would advise young people to "get married before they have children, because the opportunity for a mom and a dad to help guide the life of a child gives them such an enormous advantage," reports said.
Social conservatives were slow to back Romney during the nomination fight, but on Friday, the former Massachusetts governor received a boost from his one-time GOP primary rival Rick Santorum.
Santorum, a former Pennsylvania senator, told voters at the conference that Romney's message on social issues was "solid."
"I have no doubt he understands the centrality of family. He understands the importance of family for our culture, for our economy, and for our future," said Santorum.
Santorum is a favorite of conservative religious voters and had appealed to them during the primary fight, questioning Romney’s commitment to conservative principles.
After exiting the race Santorum had delivered a lukewarm endorsement of Romney in a late-night email delivered to supporters. But on Friday, he praised the GOP standard-bearer, saying he had watched Romney "stand by those convictions that he articulated in the primaries."