Paper, the traditional gift for marking a couple's first year of marriage, also is a great choice for 250th anniversaries—especially when filling a time capsule celebrating American independence. The 2016 law creating the nonpartisan America250 commission mandated that a time capsule be buried in Philadelphia on July 4, 2026, and dug up 250 years later in 2276, reports the AP. Last week, the resulting 900-pound cylinder was sealed shut, capping years of technical design and construction, collaboration with states and meticulous review of collected items. "Once it was closed, it was a little bit anti-climactic, and then it was kind of really emotional," said Michael Berilla, who directs the fabrication technology office at the National Institute of Standards and Technology and led the team that designed and built the capsule.
Berilla's office, part of the Department of Commerce, has built encasements to protect historical documents in the past, but those tend to be stored indoors under carefully controlled conditions. With time capsules, the No. 1 enemy is water, so much of the design focused on how to keep it out. The stainless steel capsule is shaped like a cylinder, not the typical box, because square edges tend to crack and break. It will be covered with a secondary cylinder that will trap air and push out any approaching water, and the capsule itself is rimmed with a soft metal that compresses under pressure. "When you smash it shut with the lid, that metal goes into all the cracks and spaces and makes an airtight, watertight seal," Berilla said.
The items inside were at 35% relative humidity. That's moist enough to ensure they won't dry out and disintegrate, but dry enough that they won't create moisture problems. The capsule will be buried 10 feet below ground, safe from temperature fluctuations or storm damage, Berilla said. "Philadelphia would have to be six feet underwater in order for this time capsule to even possibly take on water," he said. "And if Philly is six feet underwater, you've got way bigger problems in the world." Inside the capsule are contributions from the three branches of the federal government, many of the America250 events and programs, and all 50 states, five US territories, and the District of Columbia. States submitted hundreds of letters, postcards, posters, poems, and other printed material.
The variety was fascinating, said Tom Medema, a retired National Park Service official and project manager for the time capsule. "I'm glad there wasn't really a prescription for it," he said. "I know that was hard for them, but in the end, it was just up to them to represent themselves." Berilla said when he thinks back to what America was like 250 years ago, he thinks about resilience. "And when I think forward to the future, I hope that's what they see from us," he said. "That, yes, we had it hard compared to them, but more importantly, we were diverse. We were interesting. We were creative. We worked together." For details on the capsule's contents, go here.
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