Griswold graduated from the Command and General Staff School in 1925 and the Army War College in 1929. He served with the War Department General Staff (1929–1931), was a member of the Infantry Board (1932–1936), served in the office of the chief of infantry (1936–1939), and commanded the 29th Infantry Regiment (September 1939–October 1940).
Promoted to brigadier general in October 1940, Griswold served with the 4th Infantry Division (1940–1941). Promoted to major general in August 1941, he commanded the Infantry Replacement Training Center at Camp Croft in South Carolina in 1941. Griswold then commanded first the 4th Mechanized Division (1941–1942) and then IV Corps (1942–1943). In 1943 he was assigned to head XIV Corps in the South Pacific, exchanging jobs with Alexander Patch, whose health necessitated his departure. Griswold became the senior army ground officer in the Solomon Islands.
In July 1943, with U.S. forces stalled on New Georgia, Griswold took personal charge of the assault force. Bringing in substantial reinforcements, he soon secured the island. In December, his XIV Corps replaced a Marine landing force at Empress Augusta Bay, Bougainville, and built a strong defensive perimeter there. In March 1944, his men successfully repulsed strong Japanese attacks.
Turning over their base to Australian troops beginning in March 1944, Griswold and his corps were absorbed into General Douglas MacArthur's Southwest Pacific command. Assigned to Lieutenant General Walter Krueger's Sixth Army, Griswold's corps was one of two landing on Luzon in the Philippines on 9 January 1945. After a lengthy battle and at heavy cost to combatants and civilians alike, XIV Corps liberated Manila that March. Griswold's command then cleared the southern part of Luzon. Promoted to lieutenant general in April 1945, Griswold was MacArthur's choice in June to replace the slain Lieutenant General Simon Buckner in command of the Tenth Army on Okinawa, an assignment that went instead to Lieutenant General Joseph Stilwell.
Returning to the United States, Griswold commanded the Third Army from 1945 to 1947. He retired from the army in October 1947. Griswold died in Colorado Springs, Colorado, on 28 September 1959.
Richard G. Stone
Gailey, Harry A. Bougainville, 1943–1945: The Forgotten Campaign. Lexington: University Press of Kentucky, 1991.; Hammel, Eric. Munda Trail: The New Georgia Campaign. New York: Orion, 1959.; Miller, John, Jr. United States Army in World War II: The War in the Pacific: Cartwheel, The Reduction of Rabaul. Washington, DC: Office of the Chief of Military History, Department of the Army, 1959.; Smith, Robert Ross. United States Army in World War II: The War in the Pacific: Triumph in the Philippines. Washington, DC: Office of the Chief of Military History, Department of the Army, 1963.