Okay, so. I'm working on a story set in the 1930's circus kind of era, and I'm finding it really hard to be authentic as far as the language goes. It sounds really modern. Are there databases of linguistics around that I can find, or even television shows that stay relatively faithful to the dialect? Any help would be really appreciated. Thanks in advance.

Edit: Sorry, I should specify, I'm aiming for the southern dialect. I think, I'm not American.