I rechecked my link to the Historic Aerials topo map, and for some reason it went to the default page (map of the entire US) - clicking in the address box, it went to the map of the area in question. Weird, and annoying...
Aerial images earlier than 1980 tend to be hit or miss, but it seems that the 1966 shows the branch as active, with freight cars in the curved covered loading docks at the industrial building located at Peddie and Sherman (the loading docks remain today, but the rails are long gone). There were also a decent number of freight cars in a yard located at Clinton/Alpine between Badger & Jelliff. Look to be some cars in the yard at 18th St. also, but hard to really make out (switching to 1954 view, seems a bit clearer, and a sizable amount of freight cars).
Switching to 1970, the yard at 18th seems torn up, and there doesn't seem to be any freight cars on the branch at all (well, there might be one car, hard to make out), and by 1979 (which is very clear, and in color), the yards and buildings around 18th street are torn up, and while a lot of the branch still remains (especially the grade crossings), townhouses are already starting to replace the industrial buildings that surrounded the section of the branch that ran North/South (
lets see if this 1979 Aerial view link works)