Who portrayed Rick Blaine in the classic film "Casablanca"?

Humphrey Bogart

What phenomenon causes a rainbow to form? What chemical compound is commonly used as antifreeze in car radiators? Who assassinated Robert F. Kennedy in 1968? Who was the Populist Party candidate running for U.S. President multiple times in the 1890s and early 1900s? What popular Easter candy consists of malted milk balls shaped like miniature eggs?