Are offer letters considered a contract?

In the state of Georgia. I was offered a position with a company as Exec. Asst. to the President of a company with all the terms outlined in an offer letter. I accepted the position but when I showed for work the first day they had hired another person. Whats up with that?

How did you accept the offer? Over the phone, in person verbally, or in writing?

For a contract to exist there must be:
-offer
-acceptance
-meeting of the minds (you both know what your're talking about)
-consideration (your salary, a dollar in a charity contract, etc.)

If you only rec'd an offer, and did not sign a contract, there was no contract.

sorry.