On this day in 1919, Winnipeg workers collectively launched a general strike, marking one of the most significant labour strikes in Canadian history.

They were dubbed as “Bolsheviks,” “aliens,” and “anarchists” by the media. In reporting the strike, The New York Times declared in a headline that “Bolshevism Invades Canada.”

The strike was the result of growing unrest among Canadian workers, many of whom returned from the First World War to a difficult economic environment, including factory closures, high unemployment and poor working conditions. At the heart of the strike was the principle of collective bargaining and better wages.

At 11 a.m. on May 15 nearly the entire working population of Winnipeg, including public and private sector employees, walked off the job. It is estimated that about 30,000 workers participated in the strike.

Many public utility workers went on strike, in the hopes of shutting down the city until the strikers' demands were met. While waterworks and electrical workers participated in the strike, as well as firefighters, it was not possible to shut down utilities across the entire city.

On June 10, the federal government ordered the arrest of eight strike leaders, and on June 21 thousands of strikers demonstrated in the city's Market Square.

The demonstration resulted in violence after the Royal Northwest Mounted Police began beating the protesters and opening fire on the crowds. Two strikers were killed on that day, now referred to as "Bloody Saturday," and dozens more injured.

Archival photos from that day show crowds of people surrounding an overturned streetcar, and police charging down the street on horseback to confront the protesters.

The strike was called off on June 25.

While many of the strikers’ demands were not met, many historians view the strike as having played a part in the defeat of the Conservatives in the 1921 federal election. The Liberal government that was elected in 1921 later promised to enact labour reforms.

One of the strike leaders, J.S. Woodsworth, went on to found the Co-operative Commonwealth Federation, which later became part of the New Democratic Party.