MJM,
Congrats to your son and your family! When DS received his USNA LOA, suddenly all the weight of anticipation, worry, and doubt lifted off his shoulders (and his parent's shoulders!).
As others have said, receiving a LOA is great, now you need to make sure he meets all the requirements listed in the LOA. It is a day he and your family will never forget if he receives the blue binder that has his appointment certificate in it.
DS just finished Plebe Summer, so our journey has only begun in earnest. I'm not sure my heart will make through the four years at the Academy. It bursts with pride on an ongoing basis. I Day - cool. PPW - cooler. Reform and use of cell phones - priceless.
I pray your family gets to enjoy the process of one's child becoming a USNA Midshipman. I have never encountered such joy as watching my son, in his summer whites, hug my wife (with her crying with joy, relief, and pride).
Congrats on the LOA. Oh friend, you haven't seen anything yet!