PHILADELPHIA — The United States will bury an engineered time capsule at Independence National Historical Park in Philadelphia on July 4, 2026. This action is part of a 2016 congressional mandate to honor the nation's semiquincentennial, and federal law requires the capsule to be unearthed on July 4, 2276.

The National Institute of Standards and Technology engineered the time capsule container. Mike Berilla, director of the Fabrication Technology Office at the institute, said, "The existence of a time capsule to last 250 years has never been done. We are taking on this challenge and just doubling, tripling down and saying, yeah, we're going to make another 250 years." Historical time capsules frequently failed due to water infiltration, and engineers rejected a star-shaped capsule design to avoid water infiltration risks posed by its geometric edges.

The final container design is a stainless-steel cylinder that weighs one ton when empty. The capsule will be buried 15 feet underground. U.S. law mandates the capsule to contain books, manuscripts, printed matter, memorabilia, relics, and other materials. Project organizers solicited object submissions from all 50 states, five territories, and D.C., an effort Rosie Rios, chair of America 250, said "has to be sea-to-shining-sea. It has to be grassroots community-driven. It has to be personal."

Archivists at the Library of Congress evaluated submissions, excluding materials that would decay, decompose, or damage adjacent items. Selection guidelines prohibited adhesive materials, leather, and food items from the collection. The approved collection includes an iPhone 17, Native American artwork, student essays, coins, pins, a Coca-Cola bottle, and a Civil War-era eagle feather. West Virginia submitted a piece of coal carved into the state's outline, and Ohio submitted a fragment of fabric from the original Wright Flyer along with a written statement from Orville Wright.

The capsule will also contain a thimble-sized vessel holding synthetic DNA with encoded digital archives. This DNA archive includes digital versions of Thomas Jefferson's original Declaration of Independence draft, a digital rendering of Abraham Lincoln's hand, and an audio recording of The Star-Spangled Banner. The White House Visitor Center is collecting public messages for potential inclusion. Tom Medema, project manager for the initiative, said, "The time capsule gives everybody the chance to talk to the future. It is a form of time travel for ideas and for physical things." He added, "The time capsule is all tangible things. But it is connected to ideas that are timeless. We haven't always lived up to them, but everyone around the world can agree that they are the aspiration of everybody."