Michelle Obama showed her softer side Monday night at the Democratic National Convention, declaring "I love this country" and presenting a picture-perfect image of her family on the stage in Denver.

She praised her husband as a uniter who can lead the country in a new direction, but she also used her headlining address to refine her public persona and to quiet charges from Republicans that she is somehow unpatriotic.

Barack Obama even made a surprise appearance via video feed from Kansas City, Mo., at the end of the speech, ending the first day of the convention on a light-hearted note.

"How about Michelle Obama?" he said, as their daughters tried to talk to him on screen. "Now you know why I asked her out so many times, even though she said, 'No.' You want a persistent president."

Earlier, Michelle Obama explained her love of America by saying, "I tried to give back to this country that has given me so much."

The remarks answered Republicans who ran critical Web videos in the spring that portrayed her as unpatriotic for saying during the primaries that her husband's campaign made her proud of her country "for the first time."

She said later she was talking about pride in the political process, but voters nevertheless have been slow to warm to her. A summer AP-Yahoo News poll found respondents were more apt to dislike her than Republican candidate John McCain's wife, Cindy. But polls also show that Americans don't know either woman well.

Obama re-introduced herself Monday as a caring mother from a working-class background who values family above all else. Early in the address, she talked about tucking in her daughters Malia and Sasha at night.

"I think about how one day, they'll have families of their own. And one day, they -- and your sons and daughters -- will tell their own children about what we did together in this election. They'll tell them how this time, we listened to our hopes, instead of our fears. How this time, we decided to stop doubting and to start dreaming," she said.

And she showed a personal side to Barack Obama, saying "after all that's happened these past 19 months, the Barack Obama I know today is the same man I fell in love with 19 years ago."

She continued: "Barack doesn’t care where you're from. … He knows that thread that connects us -- our belief in America’s promise."

Michelle Obama also drew enthusiastic cheers by praising Hillary Clinton for putting "those 18 million cracks in the glass ceiling" -- a reference to the failed Democratic presidential candidate's vote total in the primaries.

Obama spoke after the screening of a video tribute in which her family members and friends praised her as a thoughtful dynamo who has balanced pursuing a career with being a mother. She exited the stage with her daughters to the Stevie Wonder tune "Isn't She Lovely."

Michelle LaVaughn Robinson grew up on the South Side of Chicago in a family of modest means. She fought her way into Princeton, and later to Harvard Law School, and began dating Obama while working at a corporate law firm in Chicago. They've been married for 15 years.

Barack Obama says he considers Michelle one of his closest advisers.

The Associated Press contributed to this report.