[73] While in Manila, Mamie suffered a life-threatening stomach ailment but recovered fully. Eisenhower was promoted to the rank of permanent lieutenant colonel in 1936. He also learned to fly, making a solo flight over the Philippines in 1937, and obtained his private pilot's license in 1939 at Fort Lewis.[74][75] Also around this time, he was offered a post by the Philippine Commonwealth Government, namely by then Philippine President Manuel L. Quezon on recommendations by MacArthur, to become the chief of police of a new capital being planned, now named Quezon City, but he declined the offer.[76]
Eisenhower returned to the United States in December 1939 and was assigned as commanding officer (CO) of the 1st Battalion, 15th Infantry Regiment at Fort Lewis, Washington, later becoming the regimental executive officer. In March 1941 he was promoted to colonel and assigned as chief of staff of the newly activated IX Corps under Major General Kenyon Joyce. In June 1941, he was appointed chief of staff to General Walter Krueger, Commander of the Third Army, at Fort Sam Houston in San Antonio, Texas. After successfully participating in the Louisiana Maneuvers, he was promoted to brigadier general on October 3, 1941.