I did some searching and here's what I found:
at first I thought you were kidding, as I'd only heard of chickory on an old coffee commercial from the 70's that bragged about their use of the best chickory around.
Then I read into it. In England, Belgium and a few neighboring countries, Chickory is widely used as a salad green, but in the US, it's only purpose is in the making of, or the substituting of coffee. How weird is that?
It did say that endive can be used as a substitute, or even curly endive.
Personally, if the chickory has a "bite" like coffee, I'd rather have that!