In 1907, American coal mines killed 3,242 men in occupational accidents, probably an all-time high both for the industry and for all laboring accidents in this country. In December alone, two mines at Monongah, West Virginia, blew up, killing 362 men. Railroad accidents that same year killed another 4,534. At a single South Chicago steel plant, 46 workers died on the job. In mines and mills and on railroads, work in America had become more dangerous...