I support unions without knowing much, I know they look out for the employees, I know unions force the companies treat the resource as a human being etc. But when someone asks, these are not enough points to support my arguments on why unions are good (I don't work in a sector where unions are available, so I don't directly benefit from it).
I know organized unions played a major role in bringing us the 40-hour work week as we know today.
What other benefits were there because of unions?
Also, please mention the negatives because of it for educational purposes.