July 6, 1889 - Striking Duluth laborers were shot down by the police. In the summer of 1889, construction crews - many of them immigrants - building Duluth's streets and sewers went on strike when contractors reneged on an agreement reached the year before to pay $1.75 a day. When Mayor John Sutphin ordered police to keep strikers away from working men, fighting broke out between strikers and police, resulting in an hour-long gun fight on the corner of 20th Avenue West and Michigan Street that left two strikers and one bystander dead and an estimated 30 strikers seriously wounded. The police eventually suppressed the strike through violence, but the immigrant laborers continued to organize politically and went on to win the 1890 mayoral election.

July 6, 1892 - Striking workers battled Pinkertons -- hired detectives who were the predecessors to today's unionbusters -- at the Carnegie Steel Works in Homestead, Pennsylvania. The struggle at Homestead helped give rise to industrial unionism in the United States.