It was there, all right. I have a copy of Campbell's book 'Cooking With Soup" dated April 1 1972, which is listed as the book's eleventh printing.
It has several recipes for Chili Beef Soup, including 'chili' itself, with a can of soup and a half can water.
And to make "chili beef" for hot dogs was one can chili beef soup, 1/4 lb ground beef, 1/3 cup water and two teaspoons prepared yellow mustard. Brown the beef, add the other ingredients, and heat through.
Here is the book. The one below is dated 1970, but it's the same cover as mine. http://www.amazon.com/Cooking-With-Soup-Campbells/dp/B000FVK8K6
My 1972 edition is on ebay, offered at 2.95 and 99 cents.