The mass demonstrations occurred on a day that historically has been the province of a variety of causes. May 1 is “Loyalty Day” in the United States, first proclaimed during the administration of President Dwight D. Eisenhower in the 1950s at the peak of “Red Scare” and Cold War era.

The demonstration at Roosevelt Park was one of more than 1,000 held in every state and abroad as part of International Workers’ Day.