[1][2] His father acquired an estate at Hawksdale in Dalston through his marriage to Mary Miller (d. 1763) [3] with whom he had three daughters and three sons.
[2] In 1728 he became proctor to the Consistory Court at Carlisle and in the subsequent year was appointed joint diocesan registrar for life.
[2] Nicolson became a member of an ecclesiastical elite centered on Carlisle[1] and was active in support of the political interests of the Howards of Naworth Castle in the area from the early 1730s.
[2] His published correspondence during the period of the Jacobite rising of 1745 shows his active involvement in local politics.
[2][5] Nicholson had acquired his uncle's antiquarian collections and[6] these formed the basis of the two volume History and Antiquities of the Counties of Westmorland and Cumberland, which he compiled with Richard Burn.