There is many "variables" here, one of them being that you were pulling a trailer.
I pull my trailer with a Dodge Caravan 96, 3 litres, 300k Km on the odometer, no special towing group. Up to date, I had no problem.
The only time I had problem with overheating, not even pulling something, was once because my water pump was broken and one other time, with my Dodge Caravan 87, driving in extreme weather, south-west of USA, in Arizona.
While I can't help you to find what is the problem, here is a little tip to help reduce the motor temperature in case of overheating:
Stop the air conditionner, open the windows
put the heater and the heater fan to the maximum and enjoy! If there is coolant in the system and if the water pump is working you will cook like a chicken but the temperature should drop a little, maybe enough to bring you to a safe place.