After serving as commander of Company F, 3rd Infantry during the
Philippine–American War, Barker spent several years at
Fort Thomas, Kentucky, then served at
Fort William H. Seward, Alaska, and
Fort Lewis, Washington. From 1906 to 1908, he served at
Fort Lawton, Washington. He attended the Army Service Schools at
Fort Leavenworth,
Kansas from August 1908 to June 1911; he was an honor graduate from the
School of the Line in 1909 and graduated from the Army Staff College in 1910. After completing the Army Staff College, Barker was detailed to temporary duty with the
Signal Corps, and completed the Signal Officers Course in 1911. Barker them rejoined the 3rd Infantry, which was assigned to the Philippines during the
Moro Rebellion. He was involved in several engagements on the island of
Jolo, and was wounded at the
Second Battle of Bud Dajo, which required him to be hospitalized for six weeks. Barker received a second award of the Citation Star for his heroism. ==Later career==