 Complete the following phrase:  After the war, Baxter remained in the Army as a member of the newly-organized Medical Department, and was appointed Assistant Medical Purveyor with the rank of lieutet colonel. In 1872, he was appointed Chief Medical Purveyor, and in 1874 he received promotion to colonel. In 1875, Baxter graduated from Columbian University now George Washington University Law School with an LL.B. degree. Baxters duties as Chief Medical Purveyor included serving as personal physician to the President of the United States, and he attended James A. Garfields family. Baxter was out of town when Charles J. Guiteau 