In the intervening year, Michelle Obama put her own stamp on her position as first lady -- a job that is at once heavy with responsibility, yet at the same time, greatly undefined -- all the while getting the Obama's two children used to life in the nation's most famous home and serving as an inspiration to many women across the country.
Since her husband entered office, the first lady has attended over 200 events at the White House, visited 14 states and eight countries. Last week, she declared her first year a success.
"We're proud of our first lady," Laura Bush's former chief of staff Anita McBride said. "We want for them to be successful. We want them to represent beautifully around the world and also to be a role model for people in the country and particularly for children."
From the beginning, Obama focused her energies on children, her own as well as the nation's, and military families. But with everything she did, the media often kept an eye on her signature style, making her a regular on magazine covers and fashion blogs. People magazine declared her one of the "50 Most Beautiful" and in June, the Council of Fashion Designers of America honored her for her contributions to the fashion industry. She did not attend the ceremony, but taped a message for the audience at the gala.
"This past year has been an extraordinary time for me," Obama said, "On behalf of women everywhere, I want to thank you for making fashion liberating, inspiring, but most of all, fun."
Michelle Obama has favored belted cardigans and sleeveless sheathes over tradition Washington wear. The first lady embraces high end designers like Jason Wu, as well as more functional fashions from moderately priced stores like J.Crew.
"She doesn't dress like a first lady," Washington Post Fashion Editor Robin Givhan, who wrote the book "Michelle: Her First Year as First Lady," told "Good Morning America." I think she's changing that definition...She looks like someone that you would know as opposed to someone who looks like there's a wax statue of her somewhere."
Obama has a natural familiarity that helps her communicate so well with the people, Givhan said.
"I think it helps her to relate more to people at large, because I think women look at her and they see more of themselves in her than they would, perhaps, someone who dressed more like a traditional first lady," she said.
The Mother in Chief
Her top priority when she arrived in the White House was to help her children settle into their new, extraordinary surroundings.
"The thing that made her the happiest was that she could look at her girls and they were sane," Givhan said, reflecting on a roundtable Michelle Obama recently held with reporters. "So, in that regard, the mom in chief was very basic. It was to protect those girls and make sure that they got settled in Washington."
"Her girls are the same girls she knew, you know, when she walked into the White House on Jan. 20. That is important. Her family is settled. That was her priority," McBride said, adding that Michelle Obama and Laura Bush spoke at length about raising children at the White House, as the Obamas were moving in last January.
"I think that it [the White House] actually, at the end of the day, can be a very easy place and a warm and wonderful place to be together as a family. And by Mrs. Obama's own admission, in fact, even the president's own admission, this is the first time in a long time in their lives, certainly since their children were little, that they're all living in the same roof," McBride said, "That in itself is probably making life a little bit easier for them."
The first lady's care for children extends beyond her own family.
Just a month after her own daughters moved in, Obama invited 180 children into the White House to listen to an all female African-American a capella ensemble as part of a celebration of African-American History Month. She started an East Wing mentoring program for high school girls, and has frequently visited schools and community centers, spending time with children. She has actively encouraged others to mentor.
"I am an example of what's possible when girls from the very beginning of their lives are loved and nurtured by the people around them," she said in a speech at London's girls school in April.
Today she plans to address the U.S. Conference of Governors, focusing on childhood obesity.
It is certainly not the first time the first lady addressed healthy living.
The Healthy Host
Not long after she entered the public spotlight, the media and much of the public developed a somewhat unhealthy obsession with the first lady's arms.
Her toned arms were even the target of a joke by President Obama at the White House Correspondents Dinner. "We can all agree that Michelle has the right to bare arms," the president said to a laughing audience.
Perhaps the only thing that drew more attention than the new first lady herself was her garden. She broke ground herself on the South Lawn in March, planting the White House Kitchen Garden, with the help of local elementary school students.
"I want to make sure that our family, as well as the staff and all the people who come to the White House and eat our food, get access to really fresh vegetables and fruits," she said at the first planting.
The organic vegetable patch has provided for the first family, guests at the White House, and Miriam's Kitchen, a local soup kitchen. The first lady said the project costs about $180 for seeds and supplies to start, and has yielded 740 pounds of produce.
Obama also visited a new farmer's market near the White House, to promote eating locally grown food. There she commented that her garden – and the family dog – are hot topics.
"When I travel around the world, no matter where I've gone so far, the first thing world leaders, prime ministers, kings, queens ask me about is the White House garden. And then they ask about Bo," the first lady said, referring to the family's pet dog. "Everybody, it's the garden and Bo, or Bo and the garden, one or the other."
Obama is always quick to remind people that not so long ago, she, too, was a working mom, trying to balance it all. Even now, she says she still hasn't figured it out.
"There isn't a day that goes by, particularly after having kids, that I don't wonder or worry about whether I'm doing the right thing," she said, speaking to students at Howard University.
The First Lady's First Year
The first lady is first to admit that while she now has quite a bit of help, still she tries to make life at the White House as "normal" as she can. Like most of their peers, the Obama girls have chores and television rules. The president has long said that family, particularly his wife, keeps him grounded.
"That's the one person the president can always rely on to be the most honest with him," McBride said. "There's no one that's going to do it better than the president's wife."
For all that's been written about the first lady – be it her fashion, family or arms -- relatively little has been written about her positions on a variety of serious national issues. When speaking publicly, she sticks to familiar themes and tends to tread lightly. Despite her background as a Harvard-trained lawyer, a hospital executive – and even the president's supervisor at the law firm where they first met – Michelle Obama has yet to take on any serious political risk.
But it's a new year, and she seems poised to delve deeper into substantive policy. Her speech to the U.S. Conference of Mayors today is a precursor to what her staff is calling a "a major initiative" around the issue of childhood obesity, which she'll launch next month. The first lady has said she will make combating the epidemic a priority in her second year, vowing to get involved at a new level – even going to Capitol Hill, if needed, to get lawmakers to move on the issue.
"She is making most of her news by showing up, as opposed to by the content of her remarks," Givhan said. "I think that will change in 2010."
ABC News' Karen Travers contributed to this report.