Philadelphia Historic District Partners 250th Committee 52 Weeks of Firsts January 3 - December 26, 2026   The  52 Weeks of Firsts  is a citywide, yearlong celebration honoring Philadelphia's legacy of innovation  produced by the Philadelphia Historic District 250th Committee .  Not only was Philadelphia the birthplace of the country, but it was also the backdrop for many other marvels—some will be surprises to even the biggest Philly fans. To honor these groundbreaking inven