I just came across a very old copy of Dr Jekyll and Mr Hide which has no copyright date on it, how old is it?

My mother found a copy of this book in her boyfriends attic and gave it to me. It is a very old and weathered copy with a blue fabric-like cover with yellow/gold trim on the front. The inside reads "Printed in the United States of America by Western Printing & Lithographic Co. Racine, Washington". After that is the title page and a mini-forward pertaining to something known as "The Whitman Home Library". I suspect that this is incredibly old because there is absolutely no copyright date on the inside cover (I checked both sides), and the pages are incredibly faded and yellowed on the edges. I have no intention of selling this tome, I merely want to know how rare/old a book I have in my possession now. If anyone out there can help me, I would appreciate it immeasurably.