Green Lantern (Hal Jordan) First Appearance: Showcase #22 and How to Identify It

Green Lantern (Hal Jordan) first appeared in Showcase #22 (cover date September-October 1959), published by DC, by John Broome, Gil Kane, Joe Giella. The source puts it this way: "The very first appearance of one of DC's greatest heroes, Hal Jordan!".

• Release/cover date: the issue's release date is recorded as September 2, 1959.
• Interior story content: test pilot Hal Jordan traces a downed aircraft to the Southwest desert, where he finds the dying alien Abin Sur of the Green Lantern Corps, whose ring chooses Hal to be Earth's new Green Lantern.

• Indicia: the small print on the first page or inside cover gives the issue number, date and publisher; reprints usually say so there.
• Cover price and barcode: a price or barcode format that did not exist in the year printed means a later edition.
• Paper and staples: decades-old newsprint is tan at the edges; bright white pages on an old date are a warning sign.
• Restoration: color touch, trimmed edges and married covers are common on expensive keys; a grading service can detect them.

Shoot the front cover flat, straight on, in even light, then the indicia page and the back cover. Include the top edge and staples in one frame. The app reads the title, issue number and cover and matches it against the checks above; the indicia photo settles most reprint questions.