Lettering credit from reprint in Justice League of America Archives.
1st Justice League of America / Justice Society of America team up. Story continued in Justice League of America #22.
Story across 25 pages in three chapters of 3.67 pages, 10.67 pages, and 9.67 pages. Lettering credit from reprint in JLA Archives.
Published in cooperation with the National Social Welfare Assembly.
Previously appeared in DC comics cover-dated October 1957.
On the page immediately following page 15 of the main story sequence.
letters submitted by Don Thompson; James Wright; Douglas Marden; Dave Black