WASHINGTON – The Obama family welcomed thousands of children to the sun-soaked South Lawn of the White House on Monday for the annual Easter Egg Roll, a capital rite of spring.

The egg roll dates back to 1878, when President Rutherford B. Hayes was in office. In the main event, children race to push eggs through the grass using wooden spoons.

“Is everybody having a good time?” Obama asked the enthusiastic crowd from a balcony over the lawn. “Happy Easter everybody. We are thrilled that all of you could come.”

The theme of this year’s egg roll, “Ready, Set, Go!”, tied in with first lady Michelle Obama’s campaign against childhood obesity. The event featured basketball, yoga, dancing, gardening and healthy eating activities.

“Today we have transformed the South Lawn into a playground,” Mrs. Obama said. “And our hope today is that in addition to having fun and doing some of the traditional activities like the egg roll and the Easter egg hunt, that you can learn about beginning to live a more healthy life.”

Several National Football League players joined the effort to encourage kids to be more active by leading them through football drills. The group included Derrick Dockery, Chris Horton and Casey Rabach of the Washington Redskins, Sam Koch and Matt Lawrence of the Baltimore Ravens, and Miami Dolphins quarterback Chad Pennington.

The healthy-living theme carried over to the Storytime Stage, where Obama read “Green Eggs and Ham” by Dr. Seuss.

Obama told the children seated around the first family that the story’s moral is that you never know if you’re going to like something until you give it a try.

“When your parents tell you to eat your broccoli, you don’t know yet whether you’re going to like it or not: You’ve got to try it,” he said, with hearty agreement from Mrs. Obama, who shouted “Just try it!”

The White House said 30,000 men, women and children from all 50 states attended the egg roll throughout the day. Other activities included an arts and crafts workshop, and performances from pop star Justin Bieber and the cast of the TV show “Glee.”