I saw this animated short film at the National Underground Railroad Freedom Center in Cincinnati, Ohio on August 11 2005. It was showing as an orientation film for the museum, and I believe it was commissioned by the museum for that purpose. Per the museum web site freedomcenter.org it is still showing there.
The film is in three parts: Freedom and Unfreedom / Slavery / The Underground Railroad . Each part was done by a different animator with differing styles, and the parts were tied together with narration and an underlying musical theme. To be honest, I do not remember that much about it, but I was impressed by the differing animation techniques and the use of color. Much more information is available on the the awn.com and acmefilmworks.com sites.