Meiklejohn was commissioned a second lieutenant on 4 December 1861, promoted to lieutenant on 11 December 1862, captain on 24 May 1871, and major on 1 July 1881.
Meiklejohn received his commission as a second lieutenant on 4 December 1861, was subsequently upgraded to lieutenant on 11 December 1862, and eventually became a captain on 24 May 1871. He reached the rank of major by 1 July 1881.