Cavalcade of America
You can find more episodes in the Ear Benders section.
Here is a sample of the online episodes currently available at The Old Time Radio Fan:
Jean Laffite
1940-02-06 (6.95 MB) [30:22]
Victor Herbert
1940-06-11 (6.75 MB) [29:30]
Wild Bill Hickok
1940-11-06 (6.75 MB) [29:28]
John Brown
1940-12-11 (7.1 MB) [31:01]
The Undefended Border
1940-12-18 (7.33 MB) [32:02]