Yeah I was thinking it was probably 1939 but that 9 sure looks like an upside down 5 in the photo. Still, any ACL from the 30s is pretty early.
I've been looking at this again because it was suggested to me that the bottle was from the 50s or 60s. The Illinois Glass single digit date code changed to 2 digits (for the most part) in the 40s so that doesn't seem right to me. In addition, this bottle is embossed around the bottom with prospect hill and the town/state. All of the examples I've seen from the 50s and 60s are not embossed.