Thought, I'd add this a good book about the 9th Division in the Mekong Delta Vietnam is "The Boys of ’67: Charlie Company’s War in Vietnam" Available on Amazon.
The OG 9th Division is one of the only divisions to train together and be deployed together similar to WWII. Some of the 1st Air. Cav. in 1965 also the same.
Forrest Gump based on Forrest's Vietnam time frame 2/47th A company 9th Div.
Good book worth the read especially for those that are younger and don't understand the ramifications of Vietnam, there and at home. The Boys of '67 is based on 4/47th C company 9th Div.