Archibald McDonald was a Texan, born in Tennessee migrated to Texas as a child, and lived most of his life in Texas. He died in Oklahoma in Dec. 1919 (pension card says Jan 1920 death) but he had moved up there late in life, after 1900. Here is a link to find-a-grave:
http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRid=68831346&ref=acom
I have a record that he was mustered into service of Texas State Troops - 4th Sgt. Company B, 1st. Frontier District TST, Captain S. Shannon - enlisting March 10, 1864 and deserting April 16th.
Also found a record for him in Capt. Price's Company, 2nd Regiment Arizona Brigade Mounted Partisans. This Company became Company C of Baylors Company of Texas Cavalry, Arizona Brigade.
It looks to me that in 1864 he had enough and went to the Indian Nations for the duration. Would like to confirm with dates of Federal Service.