Please, allow me to dismiss the myth that the children of graduates find their way into USMA. They do not. Lots of angry parents, even kids with 2 USMA Old Grads as parents do not get accepted.
If it seems like the kids who go to USMA have Old Grad parents it may be that the life style and parenting style choice, awareness and know-how of having been a cadet and Army officer are more likely to generate a child with the propensity to serve and has the academic, sports and leadership achievements to successfully apply.
Trust me, there are a lot of angry Old Grads who kids do not get in each year.