After the arsenal seizure, McRae returned to White County and organized a volunteer cavalry troop, the Border Rangers, in Searcy, Arkansas, in April 1861, where he was elected and served as captain.

[2] McRae had also been appointed by Governor Henry Massey Rector to serve as the inspector general of the new Arkansas State Troops.

McRae was first sent to Camp Rector at Hopefield, (near modern-day West Memphis, Arkansas) to begin the mustering in of troops.

McRae left Hopefield shortly after the Arkansas State secession convention dispatched a political general, Thomas H. Bradley of Crittenden County, to assume command.

[2] He led his battalion in action at the Battle of Wilson’s Creek, Missouri, on 10 August 1861 and was commended for his coolness under fire and his leadership of his soldiers.

[5] McRae took part in the Battle of Pea Ridge in March 1862 and received commendations from his commander, Earl Van Dorn.

[6] During the Camden Expedition of the 1864 Red River Campaign, McRae's brigade formed part of the force under General Sterling Price.

Along with future three-term Arkansas Secretary of State Jacob Frolich, McRae headed the White County chapter of the Ku Klux Klan during Reconstruction.