Nearly eight decades have passed since Louis St. Laurent, Canada’s 12th prime minister, rolled in an open carriage through downtown streets as the Calgary Stampede parade marshal, led by red-coated Royal Canadian Mounted Police. “I shall always cherish this memory of Calgary,” St. Laurent said later that day after being given a white buckskin waistcoat by city officials in 1950. St. Laurent is one in a long line of prime ministers who have gathered at the Stampede, ranging from R. B.