In late 1944 or January of 1945, DC Comics for the first time introduced the character of Superboy to the world (who was young Superman) in the comic book issue of More Fun Comics #101. It was a mere five pages and Joe Shuster supplied the art. This went on to become an on-going strip for seven issues that chronicled young Superman's adventures until it was moved to the Adventure Comics title in issue #103 (in 1946).
In these early developing stages, Clark Kent didn't wear a suit (not until he grew up to become Superman) but he certainly used his powers like lifting cars. Sometimes he used his powers in front of his young friends (and he didn't wear glasses, not just yet...much like in CW's "Smalliville"). Young Clark finally realized that he needed a secret identity and a super suit. So Superboy was born!
The character of Superboy had initially been pitched to DC Comics in November of 1938 by Jerry Siegel but it was rejected. He tried to pitch it again two years later, but no luck. It wasn't until the popularity of Robin, the Boy Wonder that DC realized there was a market for younger Superheroes. The rest was history.
Because of the popularity of the Superboy character DC gave the Boy of Steel his own comic book in 1949 called, you guessed it, Superboy. This title is where much of the early Superman mythos were born and the pre-crisis Superboy character would enjoy publication for another 40 years until the John Byrne revamp in 1987.
Aside from the existence of the Superboy character itself (Clark Kent/Kal-EL), the first Superboy title actually ended it's run in 1977 (issue #231) and continued on as Superboy and the Legion of Superheroes for three more years. By 1980 (issue #259), Superboy left the Legion and because of this, his name was dropped from the title entirely. So it became known as simply The Legion of Superheroes which lasted until 1987. The final Legion of Superheroes issue was issue #354.