We have several excellent resources for film reviews.
In each, search the name of your film with the key words film review. Example:
Glory film review
Limit to "articles" if there are too many results.
You can also add the director's last name to further narrow the results.
Try this in PRIMO (the main library catalog) and JSTOR for popular film reviews.
For reviews of films by historians, search the title of the film and director, without "film review" in American: History and Life.
Sometimes historians will review films too.