The United States has sealed a 900-pound time capsule containing an artificial intelligence chatbot response, an orange iPhone, an eagle feather and dozens of other artefacts to give Americans living 250 years from now a snapshot of what the nation looked like during its semiquincentennial celebrations.
The capsule, made from about 400 kilograms of stainless steel, is scheduled to be buried on Saturday in Philadelphia as part of celebrations marking the 250th anniversary of American independence on July 4, 2026. It is designed to remain sealed until 2276, when it will be opened during the country’s tricentennial celebrations.
The United States’ 250th anniversary commemorates the adoption of the Declaration of Independence on July 4, 1776, an event widely regarded as the birth of the nation. The milestone celebrates the country’s founding ideals of liberty, constitutional government and popular sovereignty, while also serving as a moment of reflection on America’s history, including slavery, inequality and continuing democratic challenges.
The Philadelphia capsule is one of two major commemorative time capsules created for the anniversary. A separate capsule, intended to remain sealed until the United States marks its 500th anniversary, has also been unveiled in Washington, although its contents have largely remained confidential.
Unlike the Washington capsule, the Philadelphia collection presents a detailed portrait of contemporary America through contributions from all 50 states, five US territories and several sporting and cultural organisations.
Rosie Rios, chairwoman of America250, the body coordinating the anniversary celebrations, said the collection was intended to preserve a broad record of the nation at a defining historical moment.
“Together it all makes for ‘a representative record of the United States at 250 years,'” Rios said.
Among the historical artefacts included is a brown feather from “Old Abe,” the famous bald eagle that served as the mascot of Union soldiers during more than 30 battles in the American Civil War. The feather was contributed by Wisconsin.
Ohio donated a fragment of fabric from the Wright brothers’ aircraft that achieved the world’s first sustained powered flight in 1903, while Maine contributed a bone from the endangered North Atlantic right whale.
Several states highlighted modern technology and contemporary culture in their selections.
California submitted a printed response generated by the artificial intelligence chatbot Claude after it was prompted to predict what the state would look like 250 years after July 4, 2026.
America250 also included a late-model orange iPhone, reflecting the central role smartphones play in everyday American life.
Other items packed into the capsule include a handcrafted bookmark from the Wabanaki Native American tribe, a diamond from Arkansas, a traditional anise-flavoured cookie recipe from New Mexico and a commemorative pin celebrating the Oklahoma City Thunder’s 2025 NBA championship victory.
Not every proposed item was accepted. A leather American football was excluded after engineers concluded it would likely deteriorate before the capsule is opened.
The capsule’s designer, National Institute of Standards and Technology mechanical engineer Jay Nanninga, said preserving the contents for two and a half centuries required extensive engineering.
After evaluating several possible designs, including square and star-shaped structures, engineers ultimately selected a stainless steel cylinder because it minimised seams and joints that could allow deterioration.
The cylinder will be enclosed inside a metallic bell that creates an air pocket to keep moisture away from the sealed chamber. Engineers also added a thin layer of indium, a soft, malleable metal that provides an additional airtight seal.
Documents intended for future readers have been stored in a separate sealed compartment, while the remaining artefacts have been carefully packed in cardboard containers inside the capsule.
Drawing on decades of research into the durability of stainless steel, Nanninga expressed confidence that the capsule would survive intact.
“I do think in 250 years all the stainless will be in really good shape,” he said.
The project continues a long American tradition of preserving history through time capsules.
A capsule buried during the nation’s centennial celebrations in 1876 was opened exactly 100 years later in 1976. Another created during the bicentennial remains preserved at the National Archives and is scheduled to be opened in 2076.
Rios said the latest capsule is intended to provide future generations with an authentic picture of the United States in its 250th year.
“When the new capsule buried in Philadelphia is finally opened in 2276, we want future generations to have a clear, authentic window into who we were at 250,” she said.
“What we valued, what we built, and how we saw ourselves as a nation.”
