Conference of hundreds of industrial unionists in Chicago leads to formation of IWW, the Industrial Workers of the World, also known as Wobblies - 1905

The New York City subway, the first rapid-transit system in America, opens. More than 100 workers died during the construction of the first 13 miles of tunnels and track - 1904

Fifty thousand members of the Amalgamated Meat Cutters and Butcher Workmen employed in meatpacking plants walk off their jobs; demands include equalization of wages and conditions throughout U.S. plants - 1904