A time capsule meant to be opened in 250 years will be buried in Philly next week

Next week, Philadelphia will begin a centuries-long stint as the host of a time capsule that is not meant to be unearthed for a quarter of a millennium.

Set to be buried on July Fourth at Independence National Historical Park, the time capsule comes to the city as part of the celebrations surrounding the United States’ Semiquincentennial. After its burial, it is not slated to be seen again until 2276.

Known officially as “America’s Time Capsule,” it features items from every U.S. state and territory, as well as contributions from the three branches of government. Its creation was led by America250, a national, nonpartisan organization that Congress placed in charge of the 250th birthday celebrations.

Weighing in at 900 pounds, the time capsule — a massive cylinder emblazoned with an “America250” logo on its side — was sealed shut last week at a ceremony in Gaithersburg, Md. Its unveiling 250 years from now is intended to show future generations “the care, pride, and optimism with which Americans marked our 250th anniversary,” said America250 chair Rosie Rios in a statement.

Inside the capsule, which is constructed of stainless steel, archival contents sit organized largely in small boxes, with paper documents in a separate compartment. Many states submitted hundreds of letters, postcards, posters, poems, and other printed material for inclusion.

America250 has posted a detailed list of all the items included in the time capsule. Pennsylvania, for example, contributed a letter from Gov. Josh Shapiro, as well as an archival booklet. New Jersey, meanwhile, ponied up a stainless steel plate inscribed with a greeting for the time capsule’s future openers. And Delaware sent in a set of a dozen notecards from residents detailing their thoughts on what the state means to them.

There were some guidelines on what states could submit, as items that could degrade or rust were not allowed. Maryland, as a result, was not able to submit Old Bay seasoning, the Associated Press reported.

Some items were innovative. A “molecular data storage device” from the Library of Congress was included, and it contains synthetic DNA encoded with copies of several items from the library’s collection — including a draft of the Declaration of Independence, handwritten lyrics for “The Star-Spangled Banner,” and a 3-D rendering of President Abraham Lincoln’s hand, America250 said.

Items were sealed inside at 35% relative humidity to make sure they did not dry out or disintegrate, as well as to keep them from decaying due to moisture issues. The capsule is slated to be buried 10 feet below ground, which should keep it from being damaged by swings in temperature or storms.

“Philadelphia would have to be six feet underwater in order for this time capsule to even possibly take on water,” Michael Berilla, director of fabrication technology at the National Institute of Standards and Technology, told the AP. ”And if Philly is six feet underwater, you’ve got way bigger problems in the world.”

Congress dedicated the time capsule in a ceremony Wednesday. Thomas Austin, architect of the Capitol, said it includes a passage from the Declaration of Independence on its front.

“For those who have the privilege to work here in the Capitol, you get a sense that you are just one chapter in a long history book,” Austin said. “The U.S. Capitol is a symbol of that history. In fact, it is the symbol of that American history.”

This is not the first time capsule project undertaken by the United States. In 1976, President Gerald Ford opened a “Century Safe” that had been created a century before, and the country that year created a Bicentennial capsule that is to be opened in 2076.

The time capsule set to be buried in Philadelphia on July Fourth, meanwhile, will be marked with a capstone that includes information about its contents and creation. Additional details about the time capsule’s burial were still forthcoming Friday, according to the America250 website.

This article contains information from the Associated Press.