Aug. 20 (UPI) -- On this date in history:
In 1741, Danish navigator Vitus Jonas Bering discovered what is now called Alaska.
In 1858, theories by Charles Darwin and Alfred Russel Wallace regarding evolution were published in a British scholarly journal.
In 1968, about 200,000 Warsaw Pact troops and 5,000 tanks invaded Czechoslovakia to crush the "Prague Spring" -- a brief period of efforts to democratize socialism in the country.
In 1977, the first U.S. Voyager spacecraft -- one of two launched in 1977 -- left Cape Canaveral, Fla., bound for Jupiter and Saturn. The two Voyager space probes are still transmitting data.
In 1986, postal worker Patrick Henry Sherrill killed 14 fellow workers and wounded six others in the Edmond, Okla., post office before killing himself.
In 1989, 18-year-old Eric Menendez and 21-year-old Lyle Menendez -- the Menendez brothers -- killed their parents with a gun. The brothers were arrested in March and in 1996, both were convicted and sentenced to life in prison.
In 1996, U.S. President Bill Clinton signed into law an increase in the minimum wage in two steps from $4.25 to $5.15 an hour.
In 1998, U.S. missiles struck sites in Afghanistan and Sudan said to be linked with terrorists. The attacks were in response to the bombings of the U.S. embassies in Kenya and Tanzania 13 days earlier.
In 2003, Alabama Chief Justice Roy Moore was suspended after refusing to comply with a federal court order to remove a rock inscribed with the Ten Commandments from the lobby of the state Supreme Court building.
In 2005, in his first visit to his German homeland since becoming pope, Benedict XVI told a group of Muslims that Islam and Christianity must work together to defeat terrorism.
In 2008, a Spanair jetliner crashed on takeoff in Madrid, killing 154 people and injuring many others. Observers said the left jet engine was on fire as the plane took off.
In 2009, the Libyan convicted of the 1968 bombing of Pan Am Flight 103, which exploded over Scotland killing 270 people, was freed from prison on compassionate grounds. Abdel Basset Ali al-Megrahi, who had been sentenced to life in prison in 2001, had prostate cancer. He died in May 2012.
In 2011, two U.S. hikers who said they had wandered into Iran by mistake were sentenced to eight years in an Iranian prison for espionage. They were freed one month later and returned to the United States.
In 2012, former U.S. Secretary of State Condoleezza Rice and businesswoman Darla Moore became the first female members of Georgia's Augusta National Golf Club, site of the Masters, one of golf's most prestigious events. The club had long been under attack by women's rights groups, and others, for its all-male membership.
In 2013, celebrated novelist Elmore Leonard died in Bloomfield Hill,, Mich. He was 87.
In 2014, mudslides caused by heavy rains killed about 70 people in residential areas on the outskirts of Hiroshima, Japan.
In 2016, a suicide bombing at a wedding in Gaziantep, Turkey, killed more than 50 people.