The photo popped up on ebay, and the seller believed the picture was from 1919. Athur Duray's Frontenac is seen in the image with the unique camouflage paint scheme, and this makes me believe the picture was taken in 1918. In regards to the venue I am not sure. Sheepshead Bay and Cincinnati had trees in the infield, and I don't see them here. I'm kinda leaning towards the track in Chicago.