How do you find parents who seem to not want to be found

I was born December 07, 1971 to a Jewish under aged mother and an African American father. I know that his last name was Evans, but that's all. I was relinquished to the Louise Wise Adoption Agency when I was 3. My social workers' name was Ms. Adler. It's amazing what you remember as a child...people say that small children tend not to remember much, but I suppose it has much to do with being displaced and not knowing where you will end up next. My search for them has hardly been diligent. I have always felt that they should be the ones trying to find me seeing as how they are responsible for me being here. I won't lie and say that I haven't been bitter at times about it - after all, I am 38, but I guess that's more than enough time to forget about a child you really didn't want in the first place. Mostly, I feel that I am better off not knowing but then I'm curious if they had any illnesses betwixt them that could possibly trickle down to my children or I. I am definitely cautious about dating because I would hate to inadvertently date a relative or something creepy like that...LOL!! Life can be cruel that way. As a result of my situation, I tend to be relentlessly stable. I don't move around a lot, you know, like from place to place, because in my mind they would be able to find me.....but it's obvious that they aren't looking...smh. I could go on forever, perhaps I'll give someone else a chance to speak. Any thoughts??