Philadelphia is adding to its 2026 lineup as the city prepares to mark the 250th anniversary of the United States. At an event at the National Constitution Center on Tuesday, officials announced the "52 Weeks of Firsts."

"Philadelphia has always been the home of great ideas that we've spread out into the world, great innovations and that is central to this celebration," Michael Newmuis, the city's 2026 director, said.

The events, starting in January 2026, aim to highlight things that originated in the City of Brotherly Love and Sisterly Affection. There are some more obvious firsts in Philly, like the annual Mummers Parade, or the city being home to the nation's first zoo.

Officials also want to highlight some less-well-known firsts. Newmuis pointed to one of his favorites, the first general-purpose electronic computer, ENIAC, which was developed at the University of Pennsylvania in the 1940s. The first ice cream soda was also a Philly product, and, at the event, officials highlighted the iconic Slinky toy, which was first sold at Gimbel's Department Store on Market Street.

"Just little-known things that happened here, before they happened anywhere else," Vince Stango, the executive vice president of the National Constitution Center, said.

Each Philly first will get a presentation throughout the year, highlighting how this first came to be. It will also have a large statue of a number one, adorned to match the theme.

Tuesday's announcement adds to a lineup that officials hope to be a jam-packed 2026. Major sporting events like FIFA World Cup matches and the MLB All-Star Game have already been announced.

Newmuis says the city aims to get the entire city, not just Philadelphia's historic district, involved in the festivities.

"We're about to announce not one, not two, but 20 commercial corridors throughout Philadelphia that will be transformed with some commemorative pieces," Newmuis said.

However, the historic district will obviously play a central role, both in 2026 and this year. On Tuesday, officials also announced the return of last year's Red, White and Blue To-Do celebration slated for July 2. That marks the day the founders actually voted to approve the Declaration of Independence, and the day founding father John Adams believed would become our Independence Day.

"The second day of July 1776 will be the most memorable Epoch in the history of America," a woman portraying Abigail Adams read, citing a letter the second president wrote to his wife.

"Apparently, we got that wrong for a little while, and we're trying to bring that back. The history back," Stango said.

Officials say this year's Red, White and Blue To-Do celebration will feature more floats, a longer parade and more musical entertainment. It will culminate with a block party outside the Museum of the American Revolution in Old City.

Also planned for 2025, as part of the semiquincentennial celebrations, marking the 250th anniversaries of the U.S. Army, Navy and Marine Corps.

As for the Philly firsts, officials say they know there are a lot of them, and probably plenty they haven't thought of. They want the public's help in finding all they can. You can reach out with Philly firsts that you want to see by contacting info@historicphiladelphia.org.