Ramblinman, I have a 2004 Dakota and pull a '95 21 ft Towlite - I have hauled it from SLC fully loaded with a bunch of stuff in the truck up Parley's Canyon on I-80 - 13 miles of 5 and 6% grades without a problem. A longer continuous grade than Donner's Pass. The '04 Dakotas have a lower tow rating than the '05 and up.
I have mentioned this before, 99% of the time "normal" down the 2 lane towing at less than late for work speeds, you could actually put a 21ft one of these behind crappy little car... This is "if" you are talking about occasional trips to the nearby lake/campgrounds.
If you plan to marathon across country, I suggest you get the best {diesel} pickup you can afford, and outfit it with brakes WD hitch system, and know the "car" you would have towed the same with, would been worthless when done (shot, strained and worn out).
The problems begin when you have situations, like hard braking, accident avoidance, bad weather (storms), long hills down are worse than long hills up, as brakes go out on a car not expecting/designed to stop a double the weight of the car, load.
70% of towing safely is
driver, 30% is a capable tow vehicle... get a decent pickup or van, install trailer brake controllers, possibly WD hitch and spring helpers (air shocks)... Be patient when going places, leave early so you dont rush and do stupid crap. go down hills carefully and in lower gears than when you are sunday driving.
you should be fine.
Mine is a 28+ foot long 5th wheel, the guy before me pulled it with a 6cyl toyota full size pickup, and he towed a small 16ft alumacraft boat behind that. YES, we drive carefully, no City traffic and no mountain passes for us to get to the lakes/camping areas either.
I have a 1ton dodge diesel 6spd cummings extracab I pull with, because I drive state to state, and Im more than confident I can tow for 100's of thousands of miles without worrying if any of my above situations will cause me to be risking my life, more than normal (as such for even driving on public highways and such, ya know?)