Shelby's Iron Brigade Brigade. The 3rd Brigade Combat Team, 1st Infantry Division was known as the Iron Brigade from its formation in 1917 through World War I, World War II and Vietnam, until some time in the early 2000s when, for reasons that are still unclear, the name was changed to Duke Brigade. The unit crest was an Iron Cross in a triangle, it appears that that was also changed. The 3rd Brigade of the 4th Infantry Division is also known as the Iron Brigade. Its unit crest is similar to the medals issued to veterans of the both Western and the Eastern
Battle of the Iron Triangle Thinh a few weeks earlier, but the stream could be spanned by pontoon sections. About midway between Rach Bap and the Thi Thinh crossing of Route 14, the ARVN had another small firebase. Frequent sweeps and some semi-fixed defensive positions north of Củ Chi manned by the ARVN 25th Division and Hậu Nghĩa Province RF screened the western flank of the Triangle, but PAVN resistance in the Ho Bo Woods opposite Rach Bap, and the formidable obstacle of the Saigon River, as well as a lack of resources, limited the influence that the 25th could exert on the situation within