President Barack Obama first lady Michelle Obama and their daughters Malia and Sasha help volunteers and members of Congress stuff backpacks with books, food and photographs of the first dog Bo during a United We Serve event at Fort McNair June 25 in Washington, DC.

Helping to fill 10,000 backpacks for children of military servicemen and women, the first family stuffed copies of "The Lightning Thief," by Rick Riordan, and "The Penderwicks," by Jeanne Birdsall into backpacks along with food items and a personal letter from the president and the first lady.