Today:
293 AD – The Roman Tetrarchy was established as Emperor Diocletian appointed Maximian, Galerius, and Constantius I as co-emperors to share power across the empire.
1562 – The Massacre of Vassy occurred in France, marking the beginning of the French Wars of Religion. Catholic forces, led by the Duke of Guise, attacked Huguenot worshippers, killing many.
1692 – The Salem witch trials began in colonial Massachusetts when Sarah Good, Sarah Osborne, and Tituba were accused of witchcraft. This led to a series of hearings and executions.
1781 – The Articles of Confederation were ratified by the thirteen American states, becoming the first governing document of the United States.
1803 – Ohio was officially admitted as the 17th state of the United States, although Congress did not formally recognize the admission until 1953 due to a technical oversight.
1845 – President John Tyler signed a resolution to annex Texas, paving the way for it to become the 28th U.S. state later that year.
1872 – Yellowstone National Park was established as the first national park in the world by the U.S. Congress, signed into law by President Ulysses S. Grant.
1936 – Construction officially began on the Hoover Dam, one of the largest and most ambitious engineering projects in U.S. history.
1961 – President John F. Kennedy established the Peace Corps, a program that sent American volunteers to developing countries to provide aid and promote cultural exchange.
2002 – The war in Afghanistan saw a major escalation with the launch of Operation Anaconda, a large-scale U.S.-led military offensive against Taliban and al-Qaeda forces in the Shahi-Kot Valley.