54 – The Crimson Avenger!

A panel of the Crimson Avenger from Detective Comics #20, September 1938.
The Crimson Avenger from Detective Comics #20, Sept. 1938

September 1938 also saw the debut of The Crimson Avenger in Detective Comics #20 by Jim Chambers. Basically the Crimson Avenger was a knock-off of The Green Hornet, having a mask, a gas gun and an Asian sidekick named Wing – but he is DC’s first masked hero, so I guess he deserves a mention.