[BIGLOOK]

Try here for starters. Scroll through for campaigns if you know where your Dad was during WWII or you might try looking into some of your own family records for an old letter or an address book from that time with an APO address in it. I'm sure the folks at your local VFW would be very helpful in this as well. SandRat knows lot more about Army stuff than I do and most likely has more sources for you to check.

Now.......Aloha Teenster! Where ya been?

[BIGLOOK]

One other place you might check in the county offices of your Dad’s home of record. Returning vets were required to submit separation documentation or a DD214 post release from service. It’s doubtful they’ll have in on hand but it will be archived. This might be quicker and give you something to follow up on with other searches, like his serial number and last unit.

[SandRat]

BIGLOOK has given you some sound advice.

When you contact them if you cna provide the Division/battalion/Company that he was in during WWII along with the rank that he held when he was discharge (got his Ruptured Duck Discharge emblem), that would help them help you. They may alsoask for his SSAN and/or his Service number.