The White House rolled out an official hashtag — #WHsurprise — for the event, and live-streamed President Obama, Michelle ObamaMichelle LeVaughn Robinson ObamaMichelle Obama celebrates success of ‘Black Panther’ How textbooks shape teachers — not just their students Michelle Obama dedicates Valentine's Day playlist to Barack Obama MORE and dog Bo greeting a long line of visitors in real time.

As the first couple greeted their guests, at least some of whom appeared to be former campaign volunteers that Obama thanked for their "hard work," the president demonstrated Bo on his best behavior. The Obamas' dog, whom Michelle Obama has called her "son," repeatedly obeyed the commander in chief's order to "sit."