1st appearance of the Human Torch, Jim Hammond
2nd appearance of Namor the Sub-Mariner - 8 pages of the 12-page story reprinted from Motion Picture Funnies Weekly #1
1st appearance of Dorma, Namor's cousin
1st appearance of Ka-Zar, David Rand
1st appearance of Angel, Thomas Halloway, a private detective and vigilante
1st appearance of the Masked Raider, Jim Gardley
1st comic book published by Timely, later becomes Marvel
Retitled Marvel Mystery Comics after this issue
80,000 copies were produced of the first printing with an October 1939 date on the cover
The second printing could be identified by the October 1939 date blacked out, replaced with November 1939
The first printing sold out within a week and was quickly reprinted at a quantity of 800,000, the same as Superman #1
Although published in October, the cover date was changed to have a longer on-sale period at newsstands
💰 In March 2022, a 9.2 known as the Pay Copy due to publisher notations that tracked creator payouts sold for $2.42 million