The history of Trochu dates back to the early 1900s when a small group of French aristocrats came to Canada looking for adventure and a new life. Many early settlers came from a position of wealth and were officers of the French cavalry in France. The officers left France when the state began to experience religious unrest.
Armand Trochu, a stockbroker in Paris before becoming a rancher in Alberta, founded the town. Trochu heard of the experiences and stories of ranch life and decided to go into ranching himself. He then ventured off into the open country to search for a suitable ranch site.
Armand Trochu purchased land from the Hudson's Bay Company (HBC) in 1903. He required capital and in the summer of 1904, returned to France in order to raise money. Two fellow Frenchmen, Paul de Beaudrap and his brother Roger, also came to the Trochu district. In August 1904, Paul arrived on his homestead and began building his ranch. While the Beaudrap family became settled, Armand sold the potential of the area to two of his countrymen named L.C. Eckenfelder and Joseph Devilder. Both were willing to invest money in the enterprise. During fall 1904 and early 1905, a significant number of Frenchmen came to Armand's homestead and the St. Ann Ranch Trading Company was formed in 1905. A few of the early settlers left as a result of illness and/or family reasons but, during 1906, many homesteaders arrived. As the population began to increase, businesses began to appear, including a post office and hotel.
In 1910, the Grand Trunk Pacific Company established a camp in Trochu and work began on the railroad. As soon as this occurred, the town experienced a boom. The railroad construction crews brought more business, newcomers flocked into the area and new businesses were established.