Hello Napapon, welcome to Rootschat.
Perhaps you can provide a little clarification please? Is your birth father likely to be still alive? If so Rootschat has a policy that no living persons can be researched.
If he is dead, then could we have his full name and when and where he was born? I am not clear from the heading of your post whether the surname is Furgerson/Ferguson or if this is his forename.
You mention Texas which implies that he is/was an American?