Congrats to First Lady Michelle Obama, who's celebrating a milestone birthday (the big 5-0) today! In honor of the occasion, we've scoured the past few years of White House photos to find some of our very favorite "first mom" moments. From the campaign trail to Washington DC to travels across the globe, the first lady takes a hands-on approach to motherhood, and these 20 photos are just a few of the thousands that prove it. Happy birthday, Michelle!
Source: Getty / Alex Wong