 The McCain family tree has a long heritage of American military service , with ancestors fighting as soldiers in the Indian Wars , American Revolutionary War ( due to which McCain maintains a membership with the Sons of the American Revolution ) , War of 1812 , for the Confederate States of America in the American Civil War , and in World War I. The tree also includes roguish behavior and economic success . John McCain 's maternal grandfather , Archibald Wright ( 1875 – 1971 ) , was a Mississippi native who migrated to Muskogee , Oklahoma , in his twenties , ran afoul of the law with several gambling and bootlegging charges , then became a strong @-@ willed wildcatter who prospered on land deals during the early statehood years and struck oil in the Southwest . Rich by age forty , he never worked again and became a stay @-@ at @-@ home father . Raising a family in Oklahoma and Southern California , he instilled in Roberta and her twin sister Rowena a lifelong habit of travel and adventure . There is also independent @-@ minded behavior in the family tree : Jack McCain and Roberta Wright eloped and married in a bar in Tijuana , Mexico , when Archibald Wright 's wife Myrtle objected to Roberta 's association with a sailor . 
