Could you post a photo showing it straight from the side? Seeing the profile would make it easier to identify. There is a Chippendale jug that's very similar, could be the same - certainly look like it might be the same as Anne's jug. Hers looks a little different from the one I have an image of, but since there were over 400 items made in the pattern over the course of its history (I've also heard over 600, but that may include very similar designs or different sizes of the same thing), that doesn't mean much!
Anne's right that other companies made similar designs. Just to clarify, anything with a US Glass mark isn't Chippendale; the pattern (it's a pattern, not a factory) was made by Ohio Flint, Jefferson, and Central and then in England by Davidson. Chippendale made in the US may have a "Krys-Tol" mark. It was made starting in about 1907 and sold to Davidson in 1933.
I wonder if Davidson's fluoresce in UV - that could be a clue to where a Chippendale piece was made.