President joins singing circle as first lady Michelle Obama hosts 50 girls to promote active childhood and mark 100 years of National Park ServiceSome lucky Girl Scouts got what might be the ultimate camping experience on Tuesday: an overnight sleepout in tents pitched on the White House South Lawn.It was the first time one of the country’s most well-known expanses of manicured grass had been turned into a campground, an excited Michelle Obama said as she greeted the 50 Girl Scouts who were invited to the outdoor sleepover.