S. 3705: Semiquincentennial Congressional Time Capsule Act

The Semiquincentennial Congressional Time Capsule Act became Public Law 119-79 on February 18, 2026. It directs the Architect of the Capitol to build a time capsule, fill it with items chosen by congressional leaders, and bury it in the Capitol Visitor Center on or before July 4, 2026 — the country's 250th birthday.

The contents are locked down by the four top leaders of Congress, working together: the Speaker of the House, the House Minority Leader, and the Senate Majority and Minority Leaders. They have to include one joint letter signed by all four offices, plus whatever else they agree on. Every item has to survive 250 years, so the bill limits contents to durable materials like metal or archival paper — nothing organic, nothing prone to rot.

The capsule itself is capped at 50 inches wide, 32 inches deep, and 48 inches high. The burial is timed so people can also make it to a separate time capsule ceremony on Independence Mall in Philadelphia the same day.

Then it stays sealed until July 4, 2276. On that date, whoever holds the Speaker's gavel and the Senate Majority Leader's office is supposed to present the capsule to the 244th Congress, which decides what to do with everything inside. The bill passed the Senate by unanimous consent and cleared the House by voice vote — no recorded opposition.