There are a number of web site pertaining to the 9th ID. The library has a lot of info re. troop locations & battles that specific units fought in. Finally, you can request photos from the National Archives as it pertains to the 9th ID. The Battle of the Bulge was fought approximately between Dec 16, 1944 & Jan. 25, 1945.If you have your fathers discharge papers, it has a lot of info.Knowing his regiment & company is useful when trying to find out about his army career.