On This Day, March 15: 51 killed in mass shootings at Christchurch, New Zealand, mosques

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.

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 led an expedition into Mexico to capture revolutionary leader Pancho Villa, who had staged several cross-border raids. The two-year expedition was unsuccessful.

In 1917, Czar Nicholas abdicated as ruler of Russia amid the February Revolution.

In 1939, German troops, occupying the Czech provinces in the name of Adolf Hitler, entered Prague in triumph to the hisses and catcalls of the people, who sang the Czech national anthem.

In 1965, in response to the violence witnessed in Selma, Ala., President Lyndon Johnson, in an address to Congress, proclaims that "We shall overcome," calling for voting rights for all.

In 1990, Mikhail Gorbachev was elected the first, and only, president of the Soviet Union.

In 1991, a grand jury indicted four Los Angeles police officers on felony assault charges for the beating of Rodney King. The officers' acquittals in 1992 sparked violent riots in the city.

In 2007, Palestinian leaders of Hamas and Fatah agreed to a coalition government but their platform didn't recognize Israel or renounce violence.

In 2011, protesters marched on the Syrian capital of Damascus calling for democratic reforms. Syrian security forces opened fire on the demonstrations. The uprisings, which spread across the country, were met with force, and by the end of May, more than 1,000 people had been killed by security forces.

In 2019, a gunman opened fire at two New Zealand mosques, killing 51 people, while live streaming.

In 2021, the U.S. Senate confirmed Deb Haaland as secretary of the Interior Department, making her the first Native American to serve in a presidential Cabinet.