Labor unions today: "we'll help you organize and take the legal steps to get fair treatment."
Labor unions in 1912: "take this rifle. If your boss doesn't comply with our demands, shoot him and blow up his mansion."
One of these two approaches gets immediate results.
Literally coasting off the massive military surplus and trained regiments created in the midst of American imperial expansion.
One relies on a police and surveillance state that's a century behind the modern curve, as well as a population that hadn't been subject to a lifetime's worth of anti-violence propaganda and vilification against armed rebellion.