Mrs. Romney's appearance was the highlight of the night, and it turned the proceedings into something of a his-and-hers convention.
"I read somewhere that Mitt and I have a "storybook marriage. Well, in the storybooks I read, there were never long, long, rainy winter afternoons in a house with five boys screaming at once," she said.
"A storybook marriage? No, not at all. What Mitt Romney and I have is a real marriage," she added in an appearance meant to cast her multimillionaire-businessman-turned politician in a softer, more likable light.
While there was no doubt about Romney's command over the convention, the residue of a heated campaign for the nomination was evident inside the hall.
Texas Rep. Ron Paul, who never won a primary or caucus, drew several dozen delegate votes. Earlier, his supporters chanted and booed after the convention adopted rules they opposed, but were powerless to block, to prevent those votes from being officially registered.
Opinion polls made the race a close one as the Republicans' days of pageantry and speechmaking began in earnest, and the man tapped to deliver the keynote address set the stakes.
"Conventions are always huge for a challenger, because they're the ones introducing themselves" to the voters, said New Jersey Gov. Chris Christie.
Convention planners squeezed two days of speeches and other convention business into one after scrapping Monday's scheduled opener because of fears that Isaac would make a direct hit on the Florida Gulf Coast.