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]
John Sutter
1940-06-04 (6.14 MB) [26:50]
Victor Herbert
1940-06-11 (6.75 MB) [29:30]
Wild Bill Hickok
1940-11-06 (6.75 MB) [29:28]