Different groups with different themes marched from different places to rally together in Lafayette Square in front of the White House. The largest of these was organized by SEIU and CASA. Its theme was immigration, and current policies opposed to immigration. In addition to unions, religious and Latino groups were also prominent.
After gathering in Dupont Circle, roughly a thousand people marched down Connecticut Ave. to the Square, flanked by marshals in orange vests. There were so many that taking photos of the marchers was like shooting between raindrops. Printed signs, many provided by the AFL and the SEIU, were in Spanish on one side and English on the other. The most visible prop was multiple American flags.
May Day has meant many things. It originated as a pagan celebration of Spring. After the Chicago Haymarket bombing in 1886 (on May 4), it was declared to be International Workers Day at the Second International, a meeting of mostly European socialist parties. During the Cold War, the Soviet Union celebrated IWD with major military parades. In 1958 President Eisenhower declared May 1 to be Law Day, but didn’t make it a government holiday. Now that the Cold War is over and the Soviet Union is no more, May 1st has been resurrected as International Workers Day.