I have an in-law who is under 50 that firmly believes that these unions created a middle-class. In the 60's many kids came out of high school and went to work. Some went to college then to work.
The difference came later when to opportunities for the college grads were much greater. I had to belong to a teacher union...can't say they did much for me individually, but the board of education would have been a run away train without them. It works both ways. I worked for a company in retail and I don't think any union could have gotten more for their employees than management had already given.. The retailers union was waiting at the door on a yearly basis and turned away because the company gave us so much.