my jeep is overheating?

[Chad]

couple weeks ago i was just leaving my house it was cold as alaska but i got about a mile down the road and jeep started steaming i pulled over and popped the hood i couldnt see where fluid was comming from it was steaming to much to tell but was def leaking fluid onto the ground i let it cool and went back home . ok so now when i start it i dosent seem to leak fluid but still is getting hot after about 15 min the engine starts to steam (smoke) so i shut it off i just replaced water pump about a yr ago and it dosent seem to be any fluid in the oil could my thermostat be bad or does any1 have any ideas