It was formed in December 1946 when it separated from the territory of Sainte-Catherine-de-Fossambault, following protests of this part of the population against the municipal taxes. The community was founded by Irish immigrants and once contained a substantial English-speaking population, though today it is chiefly French-speaking. Its longtime principal economic activity was the exploitation of wood bound for the shipyards of Quebec. The town is located near CFB Valcartier, an important Canadian military base.
The area was first settled in the 19th century, by mostly Irish immigrants. The place may have been named after a prominent settler family, as religious records indicated the death of a certain Richard Shannon in 1831 and Simon Shannon the next year. Further impetus to its development came around 1850 when the timber industry began and in 1860 when a sawmill was built. Around 1861, about two thirds of the population was Irish, and by 1900, half the population.
In 1905, the Shannon Post Office opened. In 1914, part of Shannon's territory was expropriated to enlarge the Valcartier military base.
In 1947, the Municipality of Shannon was officially established when it separated from the Parish Municipality of Sainte-Catherine-de-Fossambault.
Current and past citizens of Shannon, near Quebec City, are alleging in a class-action suit against the federal government that the chemical trichloroethylene seeped into the town's water supply. The lawsuit has ballooned to almost 3000 people, including many with other illnesses allegedly linked to TCE and relatives of deceased persons who once resided in Shannon. According to lawyers, the number could eventually reach as many as 6,000. TCE is a manufactured chemical that is mainly used as a solvent to remove grease from metal parts in the automotive and metals industries. It is also an ingredient in adhesives, paint removers, typewriter correction fluids and spot removers. TCE is further used as a chemical building block to make other chemicals. It was formerly used as a general anesthetic, an alternative to ether or chloroform; as a solvent in dry-cleaning; and to extract oils, caffeine and flavours from plants.
“I have no doubt that the toxicology reports have determined the direct link between the cancer incidents and the trichloroethylene in the water,” said toxicology expert Michel Charbonneau, who worked with the Pittsburgh group. The suit is scheduled to be heard in Quebec Superior Court in January 2011.