I've attempted to bite my tongue and refrained from comment here but:
As a Canadian with many close American ties and a history junkie I believe that racism played its part but was less than a "them or us " mentality that motivated fighters on either side. The economic advantages of slavery did not fall heavy upon fighters but the end result started to change a system can only be described one of the most shameful in the history of humanity. There are not many sports stories in the newspaper that bring tears to my eyes but this one did even as it was many years after the Civil war ended!
Robinson in Canada