On May 4, 1970, four students were killed and eleven others wounded when National Guardsmen opened fire on a group of students at Kent State University. The students were protesting President Richard Nixon’s April 30 announcement that U.S. forces would move into Cambodia to destroy North Vietnamese bases there.
On May 4, 1886, a riot broke out in Haymarket Square in Chicago, Illinois, as a labor protest turned into a riot, leaving more than 100 wounded and 8 police officers dead. In the aftermath, Chicago authorities charged eight men, who were either speakers in or organizers of the protest, with murder. Seven of the eight defendants received death sentences. Four of the defendants were hanged. One man scheduled for execution killed himself the day before. The governor pardoned the remaining three defendants in 1893, after they had served seven years in prison.
On May 4, 1776, Rhode Island became the first North American colony to renounce its allegiance to King George III. Ironically, Rhode Island would be the last state to ratify the U.S. Constitution more than 14 years later on May 29, 1790.