Congressman Uncovers Forgotten Capitol Tunnel Linked to Founding-Era ConstructionSecret Tunnel Beneath U.S. Capitol Revealed: Hidden Passage Dates Back to 1700sCongressman Tim Moore Discovers Secret PassageA hidden passage beneath the U.S. Capitol has recently come to light, thanks to a video shared by Congressman Tim Moore (R-NC). He explains that this passageway is believed to have been part of the original construction of the Capitol, which began in 1793. The Lincoln Room itself holds historical significance, having once served as a post office during President Abraham Lincoln's era. Today, the room is a highlight for visitors touring the Capitol, and the newly revealed tunnel adds another layer of intrigue. As Moore aptly puts it, "Construction started in the 1700s, and there are all sorts of little hidden passageways.