Philadelphia's Independence Day celebrations have already started, still a week out from the actual Fourth of July. The city kicked of its Welcome America week of events by rededicating a mural painted in the wake of the 9/11 attacks on the U.S.

"Our Flag Unfurled" is a 6,000-square-foot painting of an American flag, painted as through it were being draped off the roof of a six-story cold storage warehouse on Columbus Avenue near Spring Garden. It came together very quickly

Just days after 9/11, artist Meg Saligman asked the Mural Arts Program what they could do in response to the attacks. Almost immediately, building owner Ray Tarkowski and the Sherman Williams paint company got on board to support a giant flag mural. It was supposed to be up for just six weeks.

Flash forward 15 years, it is now one of the most recognized murals in Philadelphia, visible by long lines of traffic on I-95 and the Ben Franklin Bridge. Saligman originally painted it as a flag of mourning, not flapping victoriously in the wind.

"The flag is not designed to be a 'rah-rah, call-to-arms flag,'" said Saligman. "In my mind, it had a sadness to it."

"This speaks of patriotism, and what does patriotism mean to us today? It's a good question in today's tumultuous world," said Jane Golden, director of the Mural Arts Program. "For us, it means respecting diversity while holding up commonality. It's about unity in a way that is respectful. That's what made this flag happen in 2001, and what made it happen again now."

After 15 years, the image was deteriorating and on the short list of city murals to be restored. Golden said this summer's Democratic National Convention in Philadelphia stepped up the urgency to repair the flag. The image has been repainted and resealed to protect it from another decade of weather.

Patriotism changes over time. Fifteen years ago the flag meant something about pride, worry, and anger. Now with a presidential campaign churning, each side of the political debate wants to own patriotism according to its values. The image has not changed, but the meaning attached to it has.

“When it was painted, the flag meant one thing. Today, it might mean another. In 10 years it might mean something different,” said Saligman.