1941
See Wikipedia for what was happening around the world in 1941.
Here are some Old Time Radio episodes that aired in 1941:
Fibber McGee and Molly
The McGees Throw A Dinner Party
1941-03-04 (6.73 MB) [29:24]
Fibber McGee and Molly
Party Guests Quarantined From Teeny's Measles
1941-03-11 (6.66 MB) [29:06]
Fibber McGee and Molly
A Night Out With The Boys
1941-04-22 (6.55 MB) [28:38]
Fibber McGee and Molly
Leaving For Hollywood
1941-06-24 (6.59 MB) [28:49]
The Great Gildersleeve
The Canary Won't Sing
1941-11-30 (6.83 MB) [29:50]
Mr. District Attorney
The Museum Mystery
1941-12-10 (6.28 MB) [27:28]
Plus 31 more episodes locked away in the Random Dispenser!