Assigned to the 6th Field Artillery, June 6, 1907, Brigadier General, U.S. Army, November 15, 1910. 

Served on frontier duty, at Fort Wrangel, Alaska, January-June 1875, on duty in Europe, aide-de-camp to Montgomery C. Meigs, 1875-76. With the US Geologic Expeditions west of 100th meridian (Wheeler Survey), 1876-83. At the Artillery School and duty with his regiment, 1884-87. Instructor in mathematics and Assistant Professor of drawing, West Point, 1887-91. Special duty with  intercontinental Railway Commission in charge of surveys and explorations in Central America and making report on same, 1891-96. Duty with his regiment, Fort Riley, Kansas, 1896-98. Commanding, Light Battery M, 7th Artillery, in Puerto Rico, Spanish-American War, and in the Philippines, 1900-02.

Member of a board reporting on defense of principal harbors, Philippines, 1902. Recalled to the US, August 1902, and detailed as member of Ordnance Board and Board of Ordnance-Fortification, War Department General Staff, August 15, 1903-March 26, 1906, May 23, 1908-November 14, 1910. Military attache with Russian army in Manchuria during Russo-Japanese War, 1904-05, battles of Liaoyang, Sha River, Kukden. Commanding an artillery subpost, Fort Riley, Kansas, October 1, 1906-June 15, 1908, also President, Field Arty Examining Board, and a board to determine best type of field guns and field works.

He organized the 6th Regiment of  Field Artillery (Horse), June 1907, and commanded same to June 15, 1908. Commanding District of Hawaii, October 1, 1911-February 14, 1913. Commanding Department of Hawaii, February 15-April 3, 1913, also January 23-Mar 12, 1914. Commanding 1st Hawaiian Brigade, February 15, 1913-February  25, 1914. Member, Board of Officers on defense of Oahu, 1912-14. President, Army War College, April 23, 1914-October 12, 1916, and member, General Staff, June 3-October 12, 1916. Retired by operation of law, October 12, 1916.

Again on active duty, October 30, 1917-March 22, 1918, commanding post, Fort Sill, Oklahoma, November 1, 1917-March 19, 1918. 

He was an Episcopalian and made his home in Washington, D.C. 

He died in Washington, D.C. on January 19, 1924, and buried in Section 1, Grave 157, of Arlington National Cemetery.  His wife, Caroline Luce Walter Macomb (1857-1933), is buried with him.  Her her father was Rear Admiral Stephen Bleecker Luce, first President of the Naval War College.

Mrs. Macomb was a native of Washington. She was married in 1908 to General Macomb, who had been President of the Army War College and commanded FortSill, Oklahoma, during the World War. He died in 1924. Mrs. Macomb is survived by her sister and two newphews, Dr. Stephen B. Luce of Boston and Robert B. Luce of Puerto Rico.

MACOMB, CAROLINE LUCE
DATE OF DEATH: 02/10/1933
DATE OF INTERMENT: 02/14/1933
BURIED AT: SECTION WEST  SITE 157
ARLINGTON NATIONAL CEMETERY
 WIFE OF MONTGOMERY M. MACOMB
BRIG GEN US ARMY