By Max Shumpert: This article has been updated to reflect the most accurate information regarding best e-bikes available for those who are interested in new technology combined with traditional bikes. The best 5 available have changed, and information has been added to assist individuals in finding the best electric bicycles currently available on the market. The FAQ has also been updated.
In general, U.S. and European cycle manufacturers used to assemble cycles from their own frames and components made by other companies, although very large companies (such as Raleigh) used to make almost every part of a bicycle (including bottom brackets, axles, etc.) In recent years, those bicycle makers have greatly changed their methods of production. Now, almost none of them produce their own frames.
Connect the battery to the speed controller and the throttle. Follow the instructions included with the kit to connect each part. Typically, you’ll only need to plug the connector on the speed controller into the connector on the battery, then repeat the process for the throttle. Be sure not to touch the battery wires together, as this could create a dangerous spark! 
The other shout-out goes to Paul Bogaert who decided to close the Bike Doctor after 27 years and instead cycle tour the world with his wife. Paul had an early role in Vancouver bicycle advocacy and at bringing cycle riding to a less elitist/athletic and more everyday commuter crowd through their shop. They were among the early shops to embrace family friendly cargo bikes and appreciated the role that electric would play in making cycling more broadly appealing.
It appears Tennessee has not passed any legislation that applies to electric bicycles. Some people think the laws pertaining to a Motorized Bicycle should be used for an electric bicycle. However, a Motorized bicycle would be a gasoline powered device per state law as it is defined as "means a vehicle with two (2) or three (3) wheels, an automatic transmission, and a motor with a cylinder capacity not exceeding fifty cubic centimeters (50cc) which produces no more than two (2) brake horsepower and is capable of propelling the vehicle at a maximum design speed of no more than thirty miles per hour (30 mph) on level ground." 
Pedego’s Nationwide “Sole Source Provider” Program Expedites Bidding FOUNTAIN VALLEY, Calif., March 27, 2019 — Pedego® Electric Bikes, the nation’s Number 1 electric bike brand, presents the Pedego Patroller Edition, a high-performance electric mountain bike designed to empower law enforcement, security and safety personnel as they protect and serve. Pedego
Perhaps the cleverest thing of all about the Electric Brompton is that despite all the extra stuff, it folds up exactly the same as the non-powered variety. It's so simple, and unlike certain folding bikes we could mention, what you're left with is a genuinely small thing, rather than something that's about the size of a bike with the front wheel taken off.