I could go back to Howard Zinn's A People's History of the U.S. (and I think I will, eventually) to get the whole vine that was planted in the Constitution and its assumptions of sub-human status for Indigenous People & African Americans & Women that divided the people. It only got worse from there, with certain notable historical marker-events (which I should collect) that illustrated the essence -tial divide in what came to be known in a VERY generic way as Labor.
But all of it was/is about access to THE DEAL, who is in and who isn't. All of that goes under the heading of Economic Justice now, but it applies not only to American Indians and African Americans, but also women and any of the other less than politically-correct genders, and a certain particularly problematic subset, for its basic racial pathologies and trust issues, poor Whites.
So working toward authentic Solidarity is going to be a long hard process. As a teacher, I have a prejudice that is about how the process is a LEARNING process and my experience teaching America's teenagers is that this process MUST begin with honest power-sharing amongst everyone involved, so that everyone's free choices CAN be respected. Ignorance and hidden stuff is anti-freedom, anti-choosing, i.e. dysfunctional for everyone involved. Honest power-sharing means NO false-equivalencies in these hierarchies; those with more power must share more and I hope everyone can commit to what is appropriate to wherever everyone involved is trying to go with this effort. Does this sound familiar to you? I know about it from being around Quakers and some Occupys were trying to do it more or LESS successfully.
Here's some more current Labor background I have been reading, for illustration of what the ISSUES are that Labor must address:
http://books.google.com/books/about/Stayin_Alive.html?id=h9acQrZmpmAC