Two of the four issues are free to read online right now. The other two surface occasionally at auction. All four are in the public domain and belong to everyone.
| Issue | Date | How to Read It | Status |
|---|---|---|---|
| The Challenger #1 GCD #247718 |
1945 Undated, no price |
Not yet publicly available. Active search underway. | Rare |
| The Challenger #2 GCD #247719 |
1945–46 | Not publicly available. Copies surface at auction. Heritage Auctions July 2023, Auction #40227. | At Auction |
| The Challenger #3 GCD #247716 |
July 1946 | Free online now. ComicBookPlus.com (dlid=62009) Print reprint: Amazon ISBN 9781532878183 |
Free Online |
| The Challenger #4 GCD #247717 |
Oct–Dec 1946 | Free online now. ComicBookPlus.com (dlid=79176) | Free Online |
Grand Comics Database — Complete records for all four issues (#247716–247719).
comics.org/publisher/2540ComicBookPlus.com — Free online reading of Issues #3 and #4.
comicbookplus.com/?cid=2215Ken Quattro — "E.C. Stoner: The Forgotten Trailblazer" (April 2010).
thecomicsdetective.blogspot.comKenneth Leslie & The Challenger — Most detailed account of the comic's genesis.
tomchristopher.comQuattro, Ken — Invisible Men (Yoe Books, 2020). Definitive treatment of Black artists in Golden Age comics.
Invisible Men · Yoe Books, 2020Dalhousie University — Kenneth Leslie Fonds — Primary archival source. Open for research.
findingaids.library.dal.ca