This video presented by Paul Doroshenko of Vancouver Criminal Law outlines the creation of motor vehicle related laws in British Columbia and how they evolved into the Motor Vehicle Act of today.
I enjoyed that, will look forward to the following episodes.
I'm not sure when Washington and Oregon switched from driving on the left to driving on the right, but I don't think it was more than a few years earlier than BC; the left coast was behind the curve on this.
The oldest vintage car I've driven was a 1912 Overland that originated in Oregon, and it was right hand drive. That one came with the (extra cost option) foot throttle; that's a gas pedal - that you swivel to the right in order to go faster, using your right heel.