March 15 (UPI) -- On this date in history: In 44 B.C., Julius Caesar was assassinated by Brutus and others in Rome. A gold coin commemorating his assassination minted two years after his death was sold at auction in 2020 for $3.5 million . Advertisement In 1820, as part of the Missouri Compromise between the North and South, Maine was admitted into the Union as the 23rd state. It had been administered as a province of Massachusetts since 1647. In 1916, U.S. Army Gen. John "Black Jack" Pershing