He preached at the Middle Octorara Church, along the Susquehanna River in Pennsylvania, during the 1730s, but continued to move south and west to the frontiers of colonial civilization.
"Another group of pioneers (Ulster Scots) settled nearer the present site of Charlotte and organized the Sugaw Creek Presbyterian Church in 1755, with Rev.
A prolific writer and leader in his faith, he published numerous works, including Renewal of the Covenants, National and Solemn League; A Confession of Sins; An Engagement to Duties; and a Testimony; as they were Carried on at Middle Octorara in Pennsylvania, November 11, and The reasons of Mr. Alexander Craighead's receding from the present judicatories of this church..., 1743, both published by Benjamin Franklin.
Considered a promoter of the "Revival" and a participant in the "Great Awakening", he was a vocal critic of King George III and the Church of England.
He often preached to his flock to resist threats to their independence, and he held the rights of the common man as sacred as that of kings.