Remember that legal definitions vary greatly by state. In example, here is the South Carolina statute defining a trailer:
According to S.C. Code Ann. § 56-3-20, Trailer means every vehicle with or without motive power, other than a pole trailer, designed for carrying persons or property and for being drawn by a motor vehicle and constructed so that no part of its weight rests upon the towing vehicle. A "Pole trailer" means every vehicle without motive power designed to be drawn by another vehicle and attached to the towing vehicle by means of a reach or pole or by being boomed or otherwise secured to the towing vehicle and ordinarily used for transporting long or irregularly shaped loads such as poles, pipes, or structural members capable, generally, of sustaining themselves as beams between the supporting connections.
That clearly defines a toad vehicle as a trailer. Also note that not all states gave reciprocity; in other words, what's legal in your home state is not necessarily legal there. I, for one, simply don't want to worry over this when traveling. I bought the RV to relax and if I need to add something to make that possible, I'll add it.
2015 Legacy SR340 360RB
2014 Jeep Wrangler Unlimited Toad
Gigi, Poppy and Sadie Lady...On the road, but not full time!