My only knowledge of state adoption practices was in Ohio, and that was around 50 years ago. I had a cousin who was for many years the county probate and juvenile court judge, and he presided over all adoption cases in the county. At that time, adoptive parents had to personally appear before him in his court to legalize the adoption, generally with an attorney. It was a formal legal procedure. Something like a divorce I guess.
That is still the case. Legally, an adoption is kinda' like a divorce AND a marriage both in one. The legal ties between the birth parents and the child are severed (like a divorce) and the legal ties between the adoptive parents and the child are finalized.
At that time Ohio was definitely a closed adoption state and adoptive parents were not given information about the baby's natural parents or anything else. They were provided with a birth certificate showing the adoptive parents as the birth parents. I remember seeing some of those. There was also a legal procedure whereby the adoptee could request access to his/her true birth records once he/she reached a certain age, what age it was I don't know.
That is pretty much the description of a closed adoption, and 50 years ago that was just "the way it was" in a lot of states. In most states these days it can still be done that way IF the birth parents
choose a closed adoption. However, most states now also allow for open adoptions. In an open adoption the birth parents get to choose who they want to adopt their baby, and of course the adoptive parents have the choice on whether or not they want to pursue adopting that child. The birth parents and adoptive parents generally meet, often several times, before the baby is born and get to know each other. An agreement is usually worked out regarding how much and what kind of contact there will be between them after the adoption.
In our case the post adoption contact agreement was that we would send letters and pictures to the birth mothers at specified periods. In our case those times were 1mo, 3mos, 6mos, 1year, 2years, and 3years, which is pretty standard, and they were sent through the adoption agency. If both parties choose to have even more contact and relationship, then that can develop between them going forward.
With our oldest, the 3rd year picture packet came back to the agency as undeliverable, and that is when we lost contact with her. With our youngest, at the end of the 3 years we had an email address for her and continued sending her pictures and emails at least once a year for over 10 years before we lost contact with her.
All that is to say that the vast majority of adoptions are open these days and the old practice of a "blind" adoption where none of the parties get to know anything about each other - and the court sealing the adoption records to keep it that way - are pretty much obsolete. It only happens that way if the birth parents specifically want it to be that way, and very few people make that choice when they are given a choice. But even then, the adoptive parents always get to make a choice on which child they adopt.
Hence my original statement about getting to "pick" the child to become part of your family.
For us the wait wasn't all that long. From the point that we cleared the initial hurdles to adopt until his birth-mom chose us was about a year the first time. The second and third times it was just a few months, though both of those fell through. The fourth time was also only a few more months, but due to the two failed adoptions in between them, our boys ended up being just over 4 years apart - when we were initially hoping for there to be a little over 2 years between the siblings. So for us the wait was never that much longer than a pregnancy.
I'm sure that was also different 50 years ago too - there weren't nearly as m any unplanned pregnancies then as there are now, so the wait times were probably longer.
P.S. I looked it up and Ohio allows for an adoption to be either open or closed - just like Washington and most other states.