A native of Clarksfield, Ohio, Twaddle was raised in Briarcliff Manor, New York and graduated from Ossining High School in 1905.

After graduating from Syracuse University in 1910, he worked as an electrical engineer for two years before deciding to pursue a career in the military.

During the post-war period, he completed several military education and professional development courses, and served in several prominent staff assignments.

After the war, Twaddle's assignments included command of the Infantry Replacement Center at Camp Wolters, Texas.

[1] He was raised and educated in Clarksfield, then in Briarcliff Manor, New York, where his father managed the dairy farm of businessman V. Everit Macy.

[6] After graduating from college, Twaddle resided in Cleveland, Ohio and worked as an engineer for the National Electric Light Association.

[1] In 1912, he passed the competitive examination that qualified him to receive a United States Army commission directly from civilian life, and he was appointed a second lieutenant of Infantry.

[12] After the war, he was assigned to command the convalescent center for wounded and ill soldiers at Fort Dix, New Jersey.

[13] In addition to attending several army schools as a student in the early 1920s, Twaddle carried out duties including instructor and observer for units of the National Guard during their summer annual training periods.

[15] In the early 1930s, Twaddle was assigned to the 38th Infantry Regiment, and his duties included command of the summer Citizens' Military Training Camps held at Fort Sill, Oklahoma.

[20] With the U.S. anticipating entry into World War II, he estimated that if the act was passed, the United States would have 1.4 million service members in training by April 1941.

[21] In May 1942, Twaddle was appointed to command the 95th Infantry Division, which he activated and led through its initial organization at Camp Swift, Texas.

[26] Twaddle remained in command after the end of the war, and led the division when it returned to the United States in late June 1945.

[33] In September 1954, Twaddle was the subject of nationwide headlines after he publicly apologized at a 95th Division reunion for an incident which resulted in substantial casualties during combat.

[34] In November 1944, Company C of the division's 377th Infantry Regiment was directed to conduct a feint across the Moselle near Metz in order to conceal a real river crossing.

[34] When the feint proved unexpectedly successful, XX Corps commander Walton Walker ordered Twaddle to reinforce Company C by sending the division's 320th Engineer Battalion across the river.

[35] His foreign decorations included the French Legion of Honor (Chevalier), Croix de Guerre with Palm, and Medal of Metz.

[36] In 1971, the U.S. Army began construction of a facility near Tinker Air Force Base, Oklahoma to serve as the division headquarters.