Alexander was a farmer, settling 980 acres in Borden’s Grant in Virginia’s Shenandoah Valley. He was an elder of the Timber Ridge Presbyterian Church. Prior to the Revolutionary war, he served as a captain in the military service of the Virginia Colony and participated in the “Sandy Creek Expedition.” 

Shortly after publication of the Declaration of Independence, Alexander began serving as the high sheriff of Augusta County, Virginia. Subsequently, upon the formation of Rockbridge County from parts of Augusta and Botetourt Counties, he was commissioned as a justice of the county court of the newly created county and was appointed sheriff by Governor Patrick Henry. (See Waddell’s Annals of Augusta County, pp 242 and 254.)

Alexander was described as shorter than the common height, thickset, broad-breasted and strongly built. His face was broad and his eyes were large, black and prominent. His manner of speaking was very kind and affectionate.

Alexander died in 1780. He apparently was buried in the Muse Cemetery, the older burying ground for Timberidge Presbyterian Church, but his gravestone is now gone.