There is an old expression that “all politics is local.” But not that many people realize that the flipside of this adage is true as well: “local issues shape national politics.” A good example is the San Francisco Preparedness Day Parade bombing of July 22, 1916. At 2:06 p.m. a pipe bomb exploded on the west side of Steuart Street (which no longer exists) just south of Market Street near the Ferry Building. Ten people were killed instantly and more than 40 injured.

Because San Francisco was in the throes of numerous city-wide strikes, it was generally assumed that the bomb was union-inspired. This belief was crystalized when a handful of union members were arrested. Eventually the onus of the bombing fell on the shoulders of two men, both union activists, Thomas J. Mooney and Warren K. Billings. Both men were quickly convicted even though the evidence against them was both weak and questionable. Both were sentenced to death and it would take until 1939 – mass protests like this one – for the men to be exonerated and released from prison.