America250 Offers Look At “America’s Time Capsule” Design

America250 has unveiled the design and initial contents of “America’s Time Capsule,” a vessel to be buried at Independence National Historical Park in Philadelphia on July 4, 2026 and remain sealed until 2276. America250 is the national, nonpartisan organization charged by Congress with leading the celebration of the 250th anniversary of the signing of the Declaration of Independence.

According to America 250, “the Time Capsule reflects a national responsibility to preserve a representative record of the United States at 250 years.”

The capsule was developed in collaboration with scientists at the National Institute of Standards and Technology, preservation experts at the Library of Congress, and in coordination with the National Park Service. NIST scientists played a central role in advising on materials science and environmental durability, and the vessel will be built at the agency’s technology fabrication shop in Gaithersburg, Md.

“This is truly America’s Time Capsule,” said Rosie Rios, chair of America250. “Congress called on us to create a lasting marker of this milestone, and we have worked with the country’s leading scientific and preservation experts to do so thoughtfully and responsibly. When it is opened in 2276, we want future generations to have a clear, authentic window into who we were at 250 – what we valued, what we built, and how we saw ourselves as a nation.” 

America250 will reveal the final capsule contents ahead of July 4. The organization has already confirmed that select items from the 2026 Rose Parade, student submissions from America250’s America’s Field Trip contest, one-of-a-kind sports memorabilia, a handheld flag from an America Waves event, items from Congress, the Supreme Court and the Executive branch will all be included.

The capsule will also include contributions from all three branches of the U.S. federal government and submissions from each of the 50 states, Washington DC and five territories.

Figuring out how to house all of the items for 250 years was a particular challenge. “Because the capsule will be underground, it must be corrosion-resistant and impervious to gas and water. Building a seal to last decades is one thing, but 250 years is a whole different ballgame,” Jay Nanninga, the NIST mechanical engineer who built it, told America250. “We are using the best materials and scientific know-how, so when they open this capsule up in 250 years, the contents will be dry and intact.”

Unlike traditional box-shaped capsules, the time capsule is constructed as a precision-milled stainless steel cylindrical vessel built to NIST specifications. A metal bell jar cover will create an air pocket around the capsule to mitigate water intrusion and keep the capsule dry over the long term.

“For this project, we had to think about both symbolism and execution,” Tom Medema, special advisor and project manager, told America250. “From coordinating contributions across all three branches of government and 56 states and territories to overseeing design, materials, and testing, every step has required careful alignment. Our responsibility is to ensure that what we seal in 2026 remains protected for the people who open it in 2276.”

The capsule will be publicly displayed in Philadelphia in early July 2026 before being buried on Independence Day. The Park Service will oversee the capsule’s placement within Independence National Historical Park and incorporate its eventual opening into official park management records.