Since the 1960's the marriage rate in the US has been plummeting and the trend continues. California gave us no-fault divorce in the sixties which spawned a very aggressive, adversarial nationwide family court system where child support is based upon income and not the children's needs. For a man, divorce means that you will lose most if not all your money and you will lose 90 percent of the time you had with your children before the divorce.
There is absolutely no incentive for American men to marry or to father children if they have a professional career or even a decent job. Quite the contrary. We are now on our third generation of Americans that have experienced first hand the devastation of divorce.
Watch the movie "Divorce Corp" (2014). That explains why SMART men are wisely very hesitant to marry or even have children.