Well, they were in the forties and fifties. And during most of that time, their publisher was a woman named Helen Meyer. She reportedly had very little to do with the content of the books, above and beyond saying things like, "Let's do more issues of that Uncle Scrooge comic," but that was important. And she and the other folks at Dell Publishing did a great job of marketing and distribution. Anyway, she has just passed away at age 95 and here's the New York Times obituary.
You are perhaps curious/baffled about the relationship between her company, Dell Publishing, and Western Printing and Lithography, which was the firm that created the contents of those comics and printed them. Here's an explanation.