On this date:

In 1690, Hudson’s Bay Co. employee Henry Kelsey began a two-year journey from York Factory in what is now northern Manitoba. He’s believed to be the first white man to see the Canadian Prairies, and he was the first European to record the region’s flora and fauna. He was named governor of all the establishments of Hudson’s Bay in 1718 and during the four years he held this position, he continued to explore Canada’s north.

In 1839, legend has it that Abner Doubleday invented baseball in Cooperstown, N.Y. Exactly one century later, the National Baseball Hall of Fame and Museum opened there. Historians — and even the Hall itself — now consider the Doubleday story to be totally false.

In 1929, Anne Frank was born in Holland. Although she died in a Nazi concentration camp late in the Second World War, her diary about her family’s life in hiding in Amsterdam became world famous. She was 15 when she died of typhus at the Bergen-belsen camp in central Germany in early 1945.

In 1964, South African black nationalist leader Nelson Mandela and seven co-defendants were sentenced to life in prison for plotting to overthrow the country’s white supremacist government. Mandela, who had been in custody since 1962, was released in 1990 and later served five years as South Africa’s first black president.

In 1967, the U.S. Supreme Court struck down all state laws prohibiting or restricting interracial marriages.