Heading out of the 1968 Democratic National Convention in Chicago, the message of TIME’s portfolio of photographs could be reduced to one sentence: “The images of Chicago will haunt the Democrats during the campaign,” the magazine declared.
Nearly a half-century later, as the Democratic Party once against meets to officially select a nominee for President, that message is still true to an extent. The 1968 Chicago convention remains a key reference point for all the ways a political convention can go wrong—in particular when it comes to protests and violence on the streets. That year’s convention, which was also covered photographically in the pages of LIFE Magazine, was the scene of what TIME called “sanctioned mayhem” when left-leaning protesters clashed with the heavy-handed Chicago police force.
Chicago’s Mayor Richard J. Daley was seen as a man behind the method. By TIME’s count, he had grown the 11,900-man Chicago PD with 5,000 state National Guardsmen and 6,500 federal troops. The apex of the confrontation came the night that the convention would nominate Hubert Humphrey for president, as demonstrators, deciding what to do when refused a permit to march to the convention hall, were cornered by thousands of officers.
TIME’s cameras were there throughout the violent week, capturing images like the ones seen here.