The "iron cavalry"
The manufacturers of the Fighting Forces gum card series, and the American World in Arms series on which it was based, applied the quaint term "iron cavalry" to the new mobile warfare.
Fighting Forces - Iron Cavalry, #1 United States armored scout car; #2 United States high-speed tank; #3 flame-throwing tank; #4 Japanese scout motorcycle - c 1939
War, Memory and Popular Culture Archives - The University of Western Ontario - London, Ontario
gum cards, 7.7cm x 5.9cm