LTC Welsch was commissioned as a 2nd Lieutenant in the Field Artillery Army Reserve upon graduation from Texas A&M College in 1927.
It was the great depression when in July 1934 he entered into active duty with the Army for assignment with the Civilian Conservation Corps in New Mexico, and elsewhere throughout the southwest. In December 1940 he was assigned for duty with the 8th Corps area Quartermaster office, at Fort Sam Houston, Texas.
In August, 1941, he was reassigned to duty with the Field Artillery section of the 3rd Army, and in February 1942, detailed to the Inspector General’s Office of the War Department, in Washington, D.C. July found him as an IG on the staff of GEN Mark Clark, commander of the U.S. II Corps, and shipment to England headed for combat operations. On 8 November, the II Corps invaded North Africa at Oran. In January 1943, the Corps moved to Tunisia for combat assigned to the British 1st Army. On 8 July, the Corps, now under command of GEN Omar Bradley, invaded Sicily with GEN George S. Patton’s 7th Army.
In early September Welsch was selected by GEN Bradley as one of thirty officers to return to England to be a combat experienced nucleus to prepare the 1st Army Headquarters for the Normandy invasion. In early June 1944, he was with the 1st Army Headquarters echelon during the D Day invasion. During the subsequent land campaigns from then until March 1945, through France, Belgium, and into Germany, he primarily conducted IG investigations involving matters in front line combat areas of the 1st Army sector. On 17 December he was charged with investigating the massacre of U.S. soldiers at Malmedy by the Germans. Towards the conclusion of the Battle of the Bulge in mid-January 1945, he was wounded by enemy artillery fire, and after treatment was given a thirty day R&R state-side.
At the end of WW-II he applied for, and received, a commission in the Regular Army, as a captain in the infantry, giving up his Reserve commission as a colonel, and found himself in the new Military Police Corps. His first assignment from the Provost Marshal General was to attend the 1947-1948 session of the Army General Command and general Staff College, at Fort leavenworth, Kansas. From 1948 to late 1950 he served as the Provost Marshal with the 101st Airborne Division at Camp Breckenridge, kentucky, and at the Infantry School (and Center) at Fort Benning, Georgia. In November 1950, while in the pipeline for Korea, and upon reporting to GEN MacArthur’s HQ, LTC Welsch was given the choice of being a staff officer or commanding a Battalion, he chose the latter.
After serving as Battalion Commander, he served tours as PM at Fort Dix, New Jersey, and at Fort Sam Houston, Texas, before retiring in August 1957.