My dad went into WWI at 17 !/2. Before he was 19 the war was over and he was back in the States. In 1942 he was offered a warrant commission in the CBs. He turned that down but his brother who was 1 year younger served in the Pacific to 1946 as 2nd officer on a deep sea Tug boat. Officers normally are out at 52, unless they are Colonel/Navy Captain. They have 5 years to make General/Admiral. After that they serve at the need of their service, and can be called back when retired. By 1943 there were Colonels in their 30's. Age in was 17 1/2 for boys with parents permission. Again some slipped in at 12. Most of the older officers were retained in the US for training new troops. In 1956 I was helping Non-Commissioned Officers who went into the Korean War correct their records to show their correct age. I had a little college and they had none. Once I did one several came out of the wood works. I think wars bring out the liar in men when it comes to age. Seams to me Audie Murphy was too short or young or Both! He came out most decorated. Only records show service, and they lie also.