Marcus H. MacWillie was a politician who represented the Confederate Arizona Territory in the Congress of the Confederate States during the American Civil War. M. H. MacWillie was born circa 1836 in Inverness. Scotland. Little is known of his early life. One newspaper account has him a relative of Mississippi Governor William McWillie (1795–1869), but this seems unlikely. MacWillie passed his bar exam and established a legal practice in Texas. He later moved to Mesilla in what is now New Mexico and resumed his legal career. In early 1861 served as district judge, then chief justice, in Dr. Lewis S. Owings short-lived provisional government of the Arizona Territory (which included modern day New Mexico and Arizona).