While long-lived, the TLC underwent a number of splits and challenges as the labour movement developed. In the twentieth century the TLC faced rivals on the left in the form of syndicalist or socialist movements such as the Industrial Workers of the World and the One Big Union. In failing to respond to the demands of the mostly western workers who wanted more radical actions in the years following World War I, the TLC lost their confidence. They broke away from their AFL/TLC unions and formed the One Big Union following the Winnipeg General Strike in 1919.