- Jan 17 A group of Modoc warriors defeats the United States Army in the First Battle of the Stronghold, a part of the Modoc War.
- Jun 5 Sultan Bargash closes slave market of Zanzibar
- Sep 18 Government bond agent Jay Cooke & Co collapses, causing panic on Wall St, the start of the panic of 1873 and the Long depression
Censorship: The U.S. Congress enacts the Comstock Law, making it illegal to send any "obscene, lewd, or lascivious" books through the mail.
On March 3, 1873