Case in point No 10 in this ongoing feature is the late Johnny Hart (1931-2007). Everyone knows by now that, before he created his popular "B.C." comic strip in 1958, Johnny Hart produced gag cartoons for most of the big national cartoon-using publications, such as The Saturday Evening Post and Collier's.
The first early cartoon of his that I've posted below is from True magazine. It's in the hardcover anthology "The True Album of Cartoons", published in 1960, so it's safe to say that it appeared in True sometime in the 1950's. The other three early cartoons are from "Cartoon Annual No. 2", a paperback, pocket-sized anthology published in 1955 by Ace Books, Inc.
I can't see any visible connection to Hart's "B.C." drawing style in any of these cartoons. Yes, "we all have to start somewhere".
I'm also including a photo of Johnny Hart, lifted from "The Cartoonist Cookbook", published in 1966. Johnny Hart