This was only a couple generations removed from us. Like, my grandfather was a kid (elsewhere) when this happened.
The picture of the guns makes it look like a primary armed rebellion but apparently it was initially peaceful, and when state troops intervened, they confiscated guns from both strikers and the "armed guards" sent to break the strike.
The union called a strike for April 18, 1912.[4] Their demands were:
That the operators accept and recognize the union.
That the miners' right to free speech and peaceable assembly be restored.
That black-listing discharged workers be stopped.
That compulsory trading at company stores be ended.
That cribbing be discontinued and that 2,000 pounds of mined coal constitute a ton. That scales be
installed at mines to weigh the tonnage of the miners.
That miners be allowed to employ their own check-weighmen to check against the weights found by company check-weighmen, as provided by law.
That the two check-weighmen determine all docking penalties.