Did you know? According to the history.com site the world’s first planned time capsule debuted in 1876, when New York magazine publisher Anna Deihm assembled a “Century Safe” at the U.S. Centennial Exposition in Philadelphia.

The iron box was stuffed with 19th century relics, including a gold pen and inkstand, a book on temperance, a collection of Americans’ signatures, and snapshots of President Ulysses S. Grant and other politicians taken by photographer Mathew Brady.

After being sealed in 1879, the purple velvet-lined safe was taken to the U.S. Capitol and eventually left to languish under the East Portico.

Though nearly forgotten, it was later rediscovered, restored and unlocked on schedule in July 1976, during the nation’s bicentennial festivities. At a ceremony attended by President Gerald Ford, Senator Mike Mansfield said the opening had honored “the wish of a lady who sought to speak to us from the other side of a 100-year gulf.”