Events January–March January 1 Japan adopts the Gregorian calendar. The California Penal Code goes into effect. January 17 – American Indian Wars: Modoc War: First Battle of the Stronghold – Modoc Indians defeat the United States Army. February 11 – The Spanish Cortes deposes King Amadeus I, and proclaims the First Spanish Republic. February 12 Emilio Castelar, the former foreign minister, becomes prime minister of the new Spanish Republic. The Coinage Act of 1873 in the United States is signed into law by President Ulysses S. Grant; coming into effect on April 1, it ends bimetallism in the U.S., and places the country on the gold standard. February 20 The University of California opens its first medical school in San Francisco. British naval officer John Moresby discovers the site of Port Moresby, and claims the land for Britain. March 3 – Censorship: The United States Congress enacts the Comstock Law, making it illegal to send any "obscene, lewd, or lascivious" books through the mail. March 4 – Ulysses S. Grant is sworn in for a second term as President of the United States. March 15 – The Phi Sigma Kappa student fraternity is founded at the Massachusetts Agricultural College. March 22 – Emancipation Day for Puerto Rico: Slaves are freed (with a few exceptions). March 26 – First Aceh Expedition: A Dutch military expedition is launched to bombard Banda Aceh, capital of the Aceh Sultanate (in modern-day Indonesia), beginning the Aceh War. March 29 – The Rio Tinto Company is formed in Spain, following the February 17 purchase of the Rio Tinto Mine from the Spanish government by a British investment group. April–June April 1 – British ocean liner sinks off Nova Scotia, killing 547. April 4 – The Kennel Club, the world's first kennel club, is founded in the United Kingdom. April 15–17 – American Indian Wars: The Second Battle of the Stronghold is fought. April 19 – In Richmond, Rhode Island, 11 people perish in a train derailment, due to a bridge washout in the village of Richmond Switch (modern-day Wood River Junction). May – Henry Rose exhibits barbed wire at an Illinois county fair, which is taken up by Joseph Glidden and Jacob Haish, who invent a machine to mass-produce it. May 5 – Third Carlist War in Spain: Battle of Eraul – Carlists under General Dorregaray defeat Republicans at Eraul, near Estella. May 9 Der Gründerkrach: