Wow did you fly out and get refused at the airport in England?
Unfortunately it does happen sometimes
Sometimes they give you leave to remain in England for a day, but then you have to be ready to leave after the 24 hours have passed. Or, they'll just get you sorted with a return flight and send you back straight away once something becomes available.
That's why some people like to carry a letter from their employer, or a rental agreement, or a school contract of some sort to show you haven't just picked up and left the US. They carry them just in case they get asked about having a job, or a house to go back to, it can save a load of hassle if you get asked those things by the IO and they need proof.