On April 15, 1452, Leonardo da Vinci, the polymath of the Italian Renaissance, was born in Vinci, Italy, near Florence.
On April 15, 1783, the Continental Congress officially ratified the preliminary peace treaty with Great Britain that was signed in November 1782. Five months later, on September 3, 1783, the Treaty of Paris was signed by representatives of the United States, Great Britain, Spain and France, officially bringing an end to the Revolutionary War.
On April 15, 1945, the British 11th Armoured Division liberated the Bergen-Belsen concentration camp, discovering 53,000 prisoners inside, most half-starved and seriously ill, and another 13,000 corpses lying around the camp unburied.
On April 15, 1947, Jackie Robinson stepped onto Ebbets Field to play for the Brooklyn Dodgers, becoming the first African-American player in Major League Baseball. Eleven weeks later Larry Doby would break the color barrier in the American League with the Cleveland Indians.
On April 15, 1998, Saloth Sar, known as Cambodian dictator Pol Pot, died. He led the Khmer Rouge from 1963 until his death, and served as the General Secretary of the Communist Party of Kampuchea from 1975 to 1979. During his time in power more than one of every five Cambodians died by execution, forced labor and starvation.