During the entirety of the American Civil War, Motley was surgeon for the Confederate Army.

[3][4][5] Prior to his election to the Texas Senate, Motley had never held public office.

[4] Motley, a Democrat, was elected by a large margin to represent district 3 of the Texas Senate on February 15, 1876, defeating Republican nominee A. D.

[4] The district was composed of Panola, Rusk, and Shelby County, and he served from April 18, 1876, to January 11, 1881.

[2][3] He married Annie Henderson, the daughter of a local minister, not long after the Civil War.