During Duplessis' mandates, several significant labour strikes occurred such as the Dominion Textile in Valleyfield in 1946, the Asbestos Strike of 1949 in the Estrie region and the Murdochville copper mine strike in 1957.
The growth of Pool's Island eventually led to the growth of communities surrounding it, such as Valleyfield and Badger's Quay.
The Preston Baronetcy, of Valleyfield in the County of Perth, was created in the Baronetage of Nova Scotia on 13 March 1637 for George Preston.