I'm a Canadian citizen and back in 2000, when I was young and stupid, I stayed longer than I should have in the US. I entered only with my passport. Eventually I came back to Canada and upon trying to enter back into the US, in 2001, I was denied entry. No stamps were marked in my passport and basically it was just a slap on the wrist. It has been 14 years since then and I haven't set foot in the US since. I'm planning a trip to the US shortly, however, and I would like to know if there is any chance that may cause some kind of problem at Immigration. Any help or information would be greatly appreciated.
Even if they didn't stamp you they may have recorded something on the system.
If you are worried about being denied entry you could get a visa, and explain everything to visa official at the interview. And if you get approved you probably wouldn't have a problem entering the USA.