Hired: said they wanted to put me on a 3-year contract. Worked there a year. They never gave me anything to sign. Am I bound to anything?

I accepted a job offer in Tennessee and started working there. They mentioned me having to sign a contract and they would be bringing one to me. It has been 1 year since and I still have not been approached by anyone or given anything to sign.

In the electronic offer an email said this, "This offer is contingent upon your signing a written employment agreement."

I guess, I am worried if I left they would come after for all they have paid me since I never signed, or am I good?