I'm curious to know the role and the effectiveness in the concrete reforms that occurred during that time period. Were other groups (such as the social corporatists) more effective?
I must admit to never hearing of the social corportists, so I'm especially curious about their effectiveness.
This is a huge question.
I would check out the history of the iww and the writings and life of Eugene debs to get a feel for the levels of influence of various socialist organizations.