Cars Ambled up and down Blue Hill Avenue as pedestrians darted back and forth across the street, stopping into stores such as Roxie Sales, Bookstein Drug, and the Grove Hall Dress Shop on a busy Friday night. It had been warmer than usual that day, but the heat had begun to break around 5 p.m., as a small crowd grew outside the welfare office near Seaver Street. 

Inside were about 30 demonstrators, who had chained the doors and staged a sit-in. They refused to leave — or to let anyone else out, including the office staff — until their demands were met.

“We are tired of having our checks cut off without warning or investigation because of malicious gossip and lying officials!” read the handwritten flier. “We are tired of hostile social workers and supervisors!”

The demonstration by Mothers for Adequate Welfare went off without a hitch — until it didn’t. It was a peaceful protest that turned violent in an instant, setting off a torrent of events that cascaded down Blue Hill Avenue 50 years ago, consuming 10 blocks, lasting for three days, and now lost to history for most Bostonians.

But June 2, 1967, is a day to remember now, the day that Boston joined what some deemed the period of “Urban Riots,” a five-year span in the 1960s that touched nearly every major city in black American’s fight for civil rights. New York. Philadelphia. Los Angeles. Chicago. Cleveland. Atlanta. But not Boston. Some thought Boston, with a black population of nearly 10 percent, was immune.

It wasn’t.