8 March 2016 Last updated at 10:42 GMT
Peter Slevin, her biographer, talks about her legacy.
He looks at the first lady to do a hula hoop on the White House lawn and dance in public to Uptown Funk.
Mrs Obama has also taken a proactive stance on education and obesity among young people.
The White House's first black first lady Michelle Obama once told her aides not to "just put me on a plane, send me someplace and have me smile".