How can you tell if a Cat in the Hat book is first edition?

I'm curious, how does one discern whether a copy of Dr. Seuss's beloved "Cat in the Hat" is indeed a first edition? Are there any telltale markers or distinguishing features that separate the inaugural print run from subsequent iterations? Perhaps the publisher's details, the copyright page, or even the physical appearance of the book itself hold the key? I'm eager to learn the intricacies involved in authenticating such a cherished classic.