In 1792, seven years before his death, Peter I gave McNabs Island to his eldest son, the Honourable Peter McNab, who was widely referred to as Peter the Second (Figure 5). Peter II had been sent by his father to the family's ancestral home in Scotland where he received his education. After further studies in England, Peter returned to Halifax where he quickly assumed a leading role in the business and social life of Halifax. In 1792, he married Joanna Culliton, the daughter of one of the island residents. Following her death in 1827, he married Mrs. Margaret Hopkins of Liverpool, Nova Scotia. Peter II later became a Colonel in the Militia and, in 1838, was appointed to the Legislative Council (the so-called Council-of-Twelve). His nephew-in-law, Joseph Howe, sat on the other side of the political fence and was widely known for his strong opposition to the Council.

Peter II made the island his home, living in his father's cottage. He raised sheep and cattle and he and his tenants cleared about one-half of the island for pasture and cultivation. The constant state of war with France, and the resulting large number of British military personnel in Halifax, enabled Peter II to obtain high prices for his produce. He, like his father, brought shepherds from Scotland to tend his sheep. In 1820, Peter II was a judge of cattle at a Fair and Cattle show held by the Agricultural Society on Camp Hill.

The census of 1827 indicates that Peter II's household on the island consisted of himself and four females. The females were most likely his twin daughters Mary Ann and Sophia Louisa (aged 20), his daughter Catherine (aged 17) and an unidentified fourth daughter. In that year his wife Joanna died at 61 years of age. His other children had all married by this time. He had three male servants and one female servant. It also appears that he had owned a residence at the corner of Pleasant and South Streets in Halifax. In 1832, he married Mrs. Margaret Hopkins of Liverpool, Nova Scotia.