Palin's tour bus made a surprise visit just before midnight Saturday to Barnes & Noble Booksellers at Valley View Mall.
She thanked the crowd for coming and staying the night, and then left after about five minutes.
By Sunday morning, the size of the crowd had more than tripled.
The former governor of Alaska was in town to promote her book "Going Rogue."
She was accompanied by her daughter Piper, son Trig and parents, Chuck and Sally Heath.
She returned Sunday morning to begin autographing copies of her memoir.
Political coverage from NBC4.
And Sarah's thoughts on the event? We turn to Twitter:
"Surprise guest in Virginia- thx Tito the Builder! Still representing hardworking Americans who loves this country/protects r Constitution!"
"Landed in VA/swung by overnight campers to say "thx & we'll see u again tmorrw!" Reminiscent of Alaskan camping trips-slash-tailgate parties "