Operation Big Switch, from August to September 1953, was the final exchange of what in the Korean War?

Between 1982 and 1998, which Baltimore Oriole played and started in more than 2,600 consecutive games? Between 1990 and 2000, which state's population increased by about 66 percent, the most of any state? Between about 1325 and 1500, which people expanded from an island city to control much of Mexico? Between April and June of 1945, one of World War II's bloodiest campaigns was fought on which Pacific island? Which country lies between Cameroon and the Republic of the Congo and has been independent from France since 1960? From February 11 to July 16, 1858, the Virgin Mary was reported to have appeared 18 times at which French site? Between his 1950 and 1954 portrayals of which pirate did Robert Newton also play Blackbeard? Between July 1954 and August 1955, which Memphis label released five Elvis Presley singles?