By 6:30 a.m., runners were already at the starting line on the Parkway at 22d Street, stretching and jogging.
Some would do the half marathon, following the route to the Delaware River waterfront, then out to the zoo, peeling off in front of the Art Museum to finish along the Parkway. The rest would run the full 26.2 miles, continuing out Kelly Drive into Manayunk and back.
They were first-timers and regulars, people who ran simply for fun, and elite athletes.
Here was Capt. James Henry, 28, a physician at the Walter Reed Army Medical Center in Washington, who three years ago ran a marathon for a sergeant who died in Afghanistan. Now, he knows "myriad" more.
American soldiers in Germany, many awaiting deployment to battlefronts, chanted the countdown in a recorded performance. "Three . . . two . . . one," and, as the obligatory theme from Rocky played, the first wave of runners shot off toward City Hall.
In a few minutes, another wave followed. And more after that.
Each time, most of the runners took off outer sweatshirts or pants and draped them on the fence or left them on the ground.
Madeline Resnic, 12, was right behind them. For three years, she and other family members and friends have been collecting the discards and donating them to homeless shelters through the Philadelphia charity they founded, Clothes-Pin.
It wasn't even 7:15 a.m., and Madeline and friends were already out of bags. "Just pile them up," her father, Michael Resnic, told everyone.
They collected more than 12,000 articles of clothing Sunday, and Michael Resnic said that by the end of the day, the goods would be delivered to Our Brother's Place, a shelter at Ninth and Hamilton Streets.