One resource we should all use to explain underlying attitudes that were shared by many Americans is the annual editions of the Negro Motorist's Green Book.
In the Jim Crow era, many African Americans were denied access to lodging accommodations and other facilities while on the open road. As a result, the Green Books were created to show which businesses would serve African-Americans. Reading excepts of these guides with your students would be a powerful way to bring these racially-charged attitudes to your students. Start your lesson by asking your students the most obvious question: "Why were these guides printed in the first place?" Then lead them through a discussion of racial discrimination in public accommodations.
The Smithsonian's National Museum of American History has a terrific blog post on this subject. At the bottom, it links to a New York Public Library site that has digitized copies of the Green Book.
(Thanks to Cheryl Davis, @digitalteacher, for retweeting a blog post about the Green Books from the Smithsonian's American History Museum, and of course to the Museum for writing the original post.)