He subsequently served as Simpson's chief of staff with the 35th and 30th Infantry Divisions, the XII Corps, and Fourth and the Ninth armies.

They had three children: daughters Patricia and Mary, and a son, James Edward Moore Jr.[1] In 1927, he was sent to the Philippines, where he served with the 31st Infantry Regiment at Fort Santiago.

He was promoted to first lieutenant on 9 June 1929, and soon after returned to the United States, where he became a company commander in the 10th Infantry Regiment at Fort Thomas, Kentucky.

On 12 April he was transferred to the War Department General Staff in Washington, D.C., where he worked in the Budget and Legislative Planning Branch.

[7] In March 1942, with the United States now engaged in World War II, Moore became the chief of staff of the 35th Infantry Division at Camp San Luis Obispo, California.

[7][8] Moore and Simpson were abruptly transferred to the 30th Infantry Division at Fort Jackson, South Carolina, on 22 May 1942.

[7][10] On 13 October 1943, Simpson assumed command of the Fourth United States Army, and Moore went with him as chief of staff.

Moore was part of the advance party of the headquarters that flew to the UK on 11 May, where Simpson met with the commander of the European Theater of Operations, United States Army, General Dwight D. Eisenhower.

The main body of Ninth Army headquarters embarked for the UK on the ocean liner RMS Queen Elizabeth on 22 June.

Over a two-week period, 40,000 long tons (41,000 t) of artillery ammunition was brought forward from dumps in Normandy and the UK.

[7] Moore served at headquarters of the United States Army Pacific at Fort Shafter, Hawaii, from 1 January to 28 February 1947, when he became the Commanding General of the South Sector there.

[7] He commanded the 10th Mountain Division at Fort Riley, Kansas, until May 1951, when he was struck down with a severe case of tuberculosis, and spent the next two years at Fitzsimons Army Hospital.

[1] In April 1953 Moore was appointed commandant of the United States Army War College, and he became a major general again.

He was the United States High Commissioner to the Ryukyu Islands from 1953 to 1955, and the commanding general of the IX Corps from 1955 to 1958.

General Maxwell D. Taylor chose him as the Deputy Chief of Staff of the Army for Operations in June 1958.

[26][25] Moore died from respiratory arrest on 28 January 1986 at Walter Reed Army Medical Center,[24] and was buried in Arlington National Cemetery with his first wife Mildred.