Complex sentence: In the 1920s, vigilantes opposed to IWW organizers at California's harbor of San Pedro, kidnapped at least one organizer, subjected him to tarring and feathering, and left him in a remote location.
Split into simpler sentences: In the 1920s, vigilantes were opposed to IWW organizers at California's harbor of San Pedro. They kidnapped at least one organizer, subjected him to tarring and feathering, and left him in a remote location.