In 1916 , Minor was dispatched by '' The Call '' to Mexico to cover the American intervention there . When the " Mexican War " came to a sudden conclusion , Minor went to California for a rest . There he became deeply involved in the defense campaign of radical trade unionists Tom Mooney and Warren Billings in their highly publicized legal case accusing them of bombing of the 1916 San Francisco " Preparedness Day " parade . Minor worked full-time for a year and a half as the publicity director for the International Workers Defense League , an organization established to provide legal support and build public sympathy for Mooney and Billings and their co-defendants . Minor authored several pamphlets in 1917 and 1918 and spoke to a wide range of audiences about the alleged " frame-up " being perpetrated on the radical trade unionists
1916 San Francisco " Preparedness Day " parade
Preparedness Day Bombing
Robert Minor