An orphan, Mark Swift lived in Greenville with grade school teacher Rodney Kent, however Kent was no ordinary teacher, an inventive fellow he had, with the help and inspiration of young Mr. Swift, built a “time retarder,” a vehicle that looked like a submarine, but instead of traveling though water it traveled though time and space.Mark Swift and the Time Retarder appeared in SLAM-BANG COMICS #1-7 (Mar-Sep 1940) before making a final appearance in MASTER COMICS #7 (Oct 1940).
Christening the ship The History Express, Kent pronounced "with this time-retarder I won’t just teach history, I’ll show it to you."
Which is just what he did, each story involved the pair taking a look at what Mark Swift happened to be studying.
These were the first comic book characters whose gimmick was time travel, they however would only make it though a hand full of stories before disappearing, and while time travel would remain a staple of the comics, there would not be a time traveling hero in the comics until Rip Hunter: Time Master almost 20 years later.
It's rather humorous that the colonials are all ready to jail the girl as a witch, but don't seem to have an issue with a couple of guys appearing out of thin air in a giant metal contraption. Nothing witchcraft-y about that!
 #18 (January 1936) |  #30 (January 1937) |
 #78 (January 1941) |  #102 (January 1943) |
 #126 (January 1945) |  #138 (January 1946) |
 #150 (January 1947) |  #162 (January 1948) |
