Before labor unions gained power, police and even the army used to break up crowds of strikers. That was before we had luxuries we now take for granted, like working five days a week, and 40 hours over those days. One union in particular drew a sharper response that most: the Industrial Workers of the World, or IWW, or more often, "The Wobblies."
People with power and money went to great lengths to cripple the IWW, a story Ahmed White tells in his book Under the Iron Heel: The Wobblies and the Capitalist War on Radical Workers. War? Listen to the details and decide for yourself.