The inventive disclosures described herein pertain to an improved folding trailer that, in many embodiments, is comprised of an improved swivel jack to more-easily aid in safe trailer-folding operations, a hinged trailer tongue, an integral winch with an extended flexible coupling shaft, and an external or onboard rotational power source to drive the winch. More specifically, this folding-trailer configuration minimizes the physical exertion required of a user to fold or unfold the trailer, as well as significantly reduces the potential for serious user injury during the folding/unfolding process. The improved folding trailer also features foldable cargo-containment sides and multi-positionable tailgate, as well as removable/configurable cargo-carrying racks/rails.