The U.S. Patent Office building in Washington, D.C., nearly burns to the ground, destroying all 9,957 patents issued by the federal government to that date, as well as 7,000 related patent models.

The Old Patent Office Building is a historic building in Washington, D.C. that covers an entire city block between F and G Streets and 7th and 9th Streets NW in the Penn Quarter section of Chinatown. Built 1836–1867 in the Greek Revival style, the building first served as one of the earliest U.S. Patent Office buildings.

The 1836 U.S. Patent Office fire was the first of two major fires the U.S. Patent Office has had in its history. It occurred in Blodget's Hotel building, Washington on December 15, 1836. An initial investigation considered the possibility of arson due to suspected corruption in the Post Office, which shared the same building, but it was later ruled out. The cause was ultimately determined to be accidental. The fire is considered to be a unique point in the historical events of the Patent Office that caused policy changes.

A patent model was a handmade miniature model no larger than 12" by 12" by 12" that showed how an invention works. It was one of the most interesting early features of the United States patent system.

December 15 is the 349th day of the year in the Gregorian calendar; 16 days remain until the end of the year.