I thought I'd look at the titles that were on sale during 1939.
September 1939
Marvel Comics #1, October 1939 [published 31 Aug 39]

October 1939
Marvel Mystery Comics #2, December 1939 [published 13 Oct 39]

November 1939
Daring Mystery Comics #1, January 1940 [published 30 Oct 39]
Marvel Mystery Comics #3, January 1940 [published 17 Nov 39]

December 1939
Daring Mystery Comics #2, February 1940 [published 15 Dec 39]
Marvel Mystery Comics #4, February 1940 [published 20 Dec 39]
Not exactly building a dynasty - yet. But it was progressing.

Anarchy and Chaos are the natural state of the human race. Civilization is unnatural. It is a whim of circumstance. And Chaos must always ultimately triumph.