As Ubonjoe stated, the Ministry of Foreign Affairs is the proper place to have any document translations certified for legal use in Thailand and the US. But there may be additional paperwork required to qualify the document for legal use in the US. This process is referred to as document authentication.
I have had documents from the US authenticated for use in Thailand. I have not authenticated Thai documents for use in the US. You might want to check what additional documentation is needed to have the document fully accepted in the US.
As an example, my marriage license required an attachment from the Secy of State of the state where I was married and an attachment from the State Department. Finally, I needed an attachment from the Thai embassy in the US.
So, at a minimum, an attachment from the US embassy, and maybe more, may be needed to make your documents legal in the US.
Don