Sheldon Brown mentioned on his web site that he preferred right lever front brake operation due to the right hand having better control for right handed people, the majority. Definitely preferable for motorcyclists who are bicyclists too IMO.

The reason given for left hand front brake setups is the first I have read that makes sense to me. Probably unnecessary if you keep your wheels well trued or have a bike with disc brakes.

How far back does the left-front convention go? Not many caliper braked bikes in the states prior to the Paramount so far as I know. Something else to blame on Schwinn?