I have two daughters, both adopted from China. They are now older, so my information is more than 20 years old, and the situation does change. With that said: when we started the process, we inquired about domestic adoptions. We were told to expect a five to seven year waiting period for a healthy infant, with no guarantees at the end of the process. We were also told that if we were over 35, we would be deemed too old.
Those were rules of thumb, not iron laws. People arranging private adoptions had considerable latitude, and a lot of money was changing hands in pre-natal "support" to pregnant girls who planned to give up their kids. There is a fine line between providing support and buying a child, but I will leave it to those who went that route to get into the details.
We inquired about interracial adoptions and were told very bluntly that various activist groups made that very problematic in the U.S. The National Association of Black Social Workers, in particular, was on a crusade to ensure that black kids not be adopted by white couples. It was, of course, not put so bluntly; the stated rationale was that black kids should be raised "culturally black." The snarky retorts almost write themselves.
Then there was the option of adopting an older child, or a special needs child. Had we been experienced parents with several older children, and had we been living somewhere other than in a big city, we might have considered it. For a first child who would be raised in the city (not the far suburbs, but an inner city location), that was a bridge too far.
So we started looking abroad. There were a lot of adoptions at that time from Russia and Eastern Europe, and a lot of problems related to parental drug and alcohol use and disastrous orphanage situations. Other parts of the world had their plusses and minuses. China liked older parents, and the kids coming out of China had usually received decent care; China has people to thrown at problems, and children in orphanages get enough attention.
Last but not least, foreign adoptions are final. You do not have to worry about the birth mother getting out of jail and/or off drugs for a couple of months, and deciding she wants to get reinvolved with her child. Bottom line, in the U.S. most children who might be good candidates for adoption are aborted. If they survive that, the system favors foster care and the hope of future family reunification over certainty for adoptive parents. People don't go abroad for fun. They do it because they hit roadblocks here.
I wish there were a way to solve the paradox. That's why I wonder if orphanages of earlier times, if well run, would solve a lot of problems.