Blackhawk debuted in Military Comics #1, in August 1941 and was featured in this publication for a number of years as well as in his own self titled comic book. Created by Will Eisner, Bob Powell and Chuck Cuidera, Blackhawk was first published by Quality Comics, and later by National Periodical Publications (which turned into DC Comics).
Nicknamed Blackhawk, Janos Prohaska was the leader of a group of war pilots called the Blackhawk Squadron. They fought in World War II (WWII). Just about each member of the Blackhawk's represent an occupied country during the war. Blackhawk was originally identified as Polish, but later issues referred to him as American. His actual name was unknown until Blackhawk #242 (Aug.-Sep. 1968) revealed that his name was Bart Hawk, an American of Polish extraction. Secret Origins #45 gives October 31, 1912 as Janos Prohaska's birthday.
In 1952 a movie serial was made of the Blackhawks and years later in DC Animated Universe the Justice League cartoon featured the Blackhawks in a several episode story arch where the Justice League goes back into time to stop Vandal Savage from changing the time-line during WWII.
In the series called Arrow a gang made a fake name called the Blackhawks where a group of bankrobberrs and Green Arrow stopped the team from robbing banks in the Staring City.