I think that Mario Van Peebles movie Posse is a very important film. It is an excellent entry point film to a side of history many are not aware of. This is a story of early black settlers, cow boys and infantrymen returning from the Spanish-American War with a cache of gold. The main character Peebles is haunted by memories of his murdered father. The racism applied to the new black settlers and infantryman is explored in this film with excellent casting including Melvin Van Peebles (Marios father), Billy Zane, Stephen Baldwin and a wonderful performance by Big Daddy Kane.
One senses that Peeples strived to use as many notable black (and some not so notable - smile) actors as possible : ) Perhaps too many, some notable persons (Issac Hayes, Pamela Grier) are only scene in cameo, others briefly such as Tone Loc. The sentiment and efforts of Peebles efforts to expose these actors will be understood by some. The large cast (a feat for any director) work well and do a good job of telling the story in the classic "revenge and fight vs justice" western.
Most noteworthy was the wonderful narrative role of veteran actor Woody Strode (from Once Upon A Time In The West), who's own life was a barrier-breaker, within the context of a previous era not yet completed faded from memory. No other actor could have done this role better. Read the mini-bio on Woody Strode here as a primer: http://imdb.com/name/nm0834754/bio
The film does a good job of balancing action with a bit of sardonic humour. The dialog was excellent if a bit contemporary! And as others have mentioned the profanity was not accurate to that period. The sex scene was a bit much -- not really needed. There are some historical inaccuracies such as the seeming electronic branding of the cattle etc. But Posse is a good effort to hopefully open the door for more historical and creative works reflective of other untold stories and events. The actual photos of real cowboys at the end credits was very nice touch.