Read the excerpt from we shall not be moved.

in other words, the league had agreed to build a large and complex machine, to fit all its parts together, then set the whole in motion although they had never seen such a machine. nobody had, since this was the first "general strike" in the garment trades, also the largest strike of women workers ever known in the united states until that moment.

which historical detail can best clarify a reader’s understanding of the information in the excerpt?

unions at the time were made up primarily of men and addressed men’s working conditions.
“shirtwaists,” which are called “blouses” today, were one of the clothing items made in garment factories.
striking workers were often arrested by police and attacked by hired groups of poor women.
more than twenty thousand workers, made up of many different ethnicities, took part in the general strike.