1974 Schwinn Varsity
 

Removed rear wheel of my 1974 Schwinn Varsity, confused as to where spacer about half inch long goes when bolting wheel back to frame. It must slip over and down the axle on the cog side of the wheel. Can you guide me or give me reference site I can go to for location of spacer?

It is difficult to see what you are describing. Did you remove the nuts that hold the wheel to the back of the bike frame? Is this when you found the spacer?

You are probably right in that this spacer goes on the drive or cog side of the axle. When you put it all back together be sure that the wheel spins ok and that it is not loose.