Laura Bush and Michelle Obama sit in the private residence of the White House shortly after President Obama was first elected in November 2008. (Joyce N. Boghosia/The White House)

Dolley made her mark as the quintessential hostess. Eleanor broke new ground by tackling liberal causes. Lady Bird, we learned, was a quiet but effective counselor to her husband.

And what of Michelle — what will be her legacy?

Unlike the dozens of first ladies whose names and stories have been forgotten through the ages (ever had a dinner conversation about Anna Harrison or Jane Pierce?) the nation’s first African American first lady will surely be remembered in history books for a racial barrier broken. But what else will future generations find remarkable?

The year-long C-SPAN series “First Ladies: Influence and Image,” which launches Monday night, provides an opportunity to ponder the question.

The series starts with Martha Washington and winds through 220 years to Michelle Obama, providing one of the first deep looks at each of the 45 women who have held the title of first lady.

“Many of them are more interesting than their husbands . . . because their lives are not defined by political ambition,” said Richard Norton Smith, the presidential biographer and historian who is advising on the project.

Not that they did not have political aspirations — many did.

Two women who came soon after Martha Washington carved out the political and social proportions of the job that Michelle Obama would eventually inherit. (There’s still debate about whether being first lady is a “real” job, its duties being unofficial and unsalaried — much the same as was once said about housework and child rearing.)

Abigail Adams, the nation’s second first lady, knew the political power of the role. She wrote letter after letter to her husband in 1776 while he was serving as the Massachusetts representative to the Continental Congress in Philadelphia. “[B]y the way in the new code of laws which — I suppose it will be necessary for you to make — I desire you would remember the Ladies, and be more generous and favorable to them than your ancestors,” wrote the woman who would become known as Mrs. President.

First lady Madison, who was raised as a Quaker but expelled from the community when she married Presbyterian-reared James Madison, made the position one of preeminent hostess. She was as charming as her husband was socially awkward and actively politicked for his causes by throwing lavish parties. After the British burned the White House in 1814, it was Dolley who rented another house in Washington and began hosting there.

“She doesn’t say a whole lot about it, but she makes clear the British are not going to run us out of town,” said Edith Mayo, author of several books about first ladies and curator emeritus at the Smithsonian’s National Museum of American History.

Michelle Obama has gotten some flak from old-line Washington for not throwing herself more fully into the capital’s social scene. The Obamas have assiduously neglected the dinner-party circuit, where many presidents and first ladies throughout history have exercised their power. (The current first lady and president note that with young children, they do not have the time to be socialities, although they do make time for semi-regular date nights.)

And Michelle Obama’s political influence on her husband and his administration may not be fully known for some time. That’s not surprising. It wasn’t until years after she’d left the White House that we learned of petite, wildflower-loving Lady Bird Johnson’s sway over her husband’s professional endeavors.

“During the statement you were a little breathless and it was too much looking down and I think it was a little too fast, not enough change of pace,” she told her husband after a 1964 news conference for which she gave her husband a B-plus.

“Yes, ma’am,” President Johnson replied.

Apart from the politicking and the socializing, first ladies throughout history have been “protectors of their families,” Smith said.

In that, Michelle Obama’s impact is already clear. She has taken care to cultivate her family’s image in magazine interviews, sit-downs on TV talk shows and family portraits taken by Annie Leibovitz. Obama’s historical role model may very well be Edith Roosevelt, wife of Teddy and a mother of five who knew the press would be interested in her children’s antics.

“She injected decorum into that by showing pictures of her reading to the children, having them look like they are doing homework,” Mayo said. Roosevelt also chose the magazines in which she wanted stories about her family to appear, and she chose who she wanted to write them.

Obama has said the other Roosevelt — Eleanor — and Jacqueline Kennedy are two of the first ladies she relates to most. The two are among the most beloved and criticized to occupy that role.

Eleanor Roosevelt was the first first lady to hold a news conference. It was held in 1933, and only female reporters were invited. Kennedy spent three years in the White House, but in that short time the Queen of Camelot’s cool reserve struck some as arrogance. Years later, those rough edges have softened.

Only time will tell how the current first lady will be judged. But in an interview for the kickoff of the C-SPAN series, Obama gave an indication of how she would like to be remembered. Commenting on the work of her predecessors, she said she has followed in their path as she chose her own causes: “For me, that’s meant helping our kids lead healthier lives . . . working to get our military families the benefits and support they’ve earned . . . opening the White House to as many people as possible . . . and encouraging all our young people to achieve every last one of their dreams.”