Rip Hunter's First Appearance?

[captain_unimpressive]

I wasn't sure where to ask this question, but wheere and when was it that Rip Hunter, the DC time-traveler, was first introduced?
Someone told me that it was in "The Kingdom", but that just doesn't sound right. So, is he a classic character?

[telerites]

It was in Showcase #20 back in 1959.

Here's the GCD link http://www.comics.org/details.lasso?id=15015