Tammy, there are several ways you can leave a trail for your birthfather, in case he is looking for you.
1) Post a message on ISRR, the International Soundex Reunion Index. This is a free registry.
I can get you the blank form, if you want.
2) If your birthfather gave up his parental rights, the adoption agency would know it. Wisconsin Stat 48.432 list your rights to the information. What you can do is leave a waiver of confidentiality in the adoption file, if he is looking for you. All you have to do is contact the Department of Health and Family Services in
Madison, WI to get the form to put in the file. If he is looking for you...this will help. Jack, Manitowoc, WI