He received a grant of 1200 acres and selected this land, Dalswinton, on the Hunter River in 1825 when he accompanied William Ogilvie to the district. He had been in his Majesty's Service for almost twenty years and received another grant free of quit rent as a Naval Officer. This second grant was 1360 acres. He made improvements at Dalswinton - a dairy was built and the estate was stocked with fine woolled sheep and cattle and horses. A stone cottage, shingled, and a garden and fencing and other additions were made.
Assigned Convict Workers
The following convicts were assigned to Peter Cunningham at Dalswinton:
James Haines per Marquis Hastings assigned in 1828
Michael Shanahan per Governor Ready
Benjamin Belcher per Albion assigned in 1828
Patrick Bryan per Mangles assigned in 1826.
Departure from the Colony
Peter Cunningham was on half pay of the British navy and recalled to duty in 1830. He never returned to Dalswinton.
William White a brother of Mrs. Ogilvie of Merton occupied and managed Dalswinton until 1835 when Peter Cunninghams nephew John Pagan took over control.
Peter Cunningham's nieces Janet and Jane arrived in 1836 from Scotland with Peter Cunningham Pagan and they also lived at Dalswinton. Janet married William Tucker Evans at Dalswinton in 1839.
John Pagan obtained a license for depasturing stock in the Gwydir district in 1838. This was beyond the boundaries of the colony at this time. He was still at Dalswinton in 1842 as he imported the famous Clydesdale Galloway Lad in that year however by 1843 he had perished somewhere to the north-west of the colony. 
Peter Cunningham remained unmarried and died in 1864 aged 74 at East Greenwich.
The Gentleman's Magazine - Obituary:
March 6 1864.
At Greenwich, aged 71, Peter Miller Cunningham, Esq., Surgeon R.N. The deceased, who was the younger brother of Thomas Mounsey Cunningham (a well known name in Scottish provincial literature), and of Allan Cunningham, was born at Dalswinton, near Dumfries, in November, 1789, and received his baptismal names from that Peter Miller who is generally recognised as the first person to make use of steam in propelling boats.
He received his medical education at the University of Edinburgh, and as soon as he attained the requisite age, was appointed an Assistant Surgeon in the Royal Navy. In this capacity he saw service on the shores of Spain, where the great war was raging, and on the lakes of America, where he became the close friend of the celebrated Clapperton. He also served for some years in the Eastern Archipelago, and had ample opportunities of observing the effect of tropical climates on the European constitution.
Of this he profited when, peace having arrived, he was thrown out of the regular line of duty, and would have been left to vegetate on half-pay if he had not sought other employment from the Admiralty; in the course of which, to use the words of the Quarterly Review, he made no less than four voyages to New South Wales, as Surgeon Superintendent of convict ships, in which were transported upwards of six hundred convicts of both sexes, whom he saw landed at Sydney without the loss of a single individual: - a fact of itself quite sufficient to attest his judgment and ability in the treatment and management of a set of beings not easily kept in order. - (Q. R., Jan. 1828.)
The result of his observations during this period was embodied in his' Two Years in New South Wales, which was published in 1827, in 2 vols., post 8vo., and rapidly ran through three large editions. This work is both amusing and instructive, and although necessarily superseded by more recent works on the same ever-extending subject, is still frequently quoted, and some centuries hence will afford a mine of information and speculation to the correspondents of the Sylvanus Urban of the Antipodes. Mr. Cunningham added the profits arising from this work to his early savings in the Navy, and expended them in an attempt to open up a large tract of land in what he then fondly regarded as his adopted country. But the locality was perhaps badly chosen; the seasons were certainly unpropitious, and he soon abandoned the struggle as far as his own personal superintendence was concerned.
His well-earned reputation at the Admiralty, however, speedily procured him employment, and he served successively in the Tyne, 18, on the South American Station, and in the Asia, 84, in the Mediterranean (app to H.M.S. Asia 18 March 1836, Navy List). In the course of these years he published a volume of essays on Electricity and Magnetism, and another on Irrigation as practised on the Eastern Shores of the Mediterranean. 'He also contributed an account of a Visit to the Falkland Islands to the Athenaeum and was a frequent writer in other periodicals. He was a man of remarkable powers of observation, and of the most amiable and conciliatory disposition; and, it is believed, passed through life without making a single enemy.
His attachment to his brother Allan was particularly strong, and although death had separated them for more than twenty years, the name of that brother was among the last articulate sounds which passed his lips. It was well remarked by the Quarterly Reviewer, in the article before quoted, that the appearance of two such men, in one humble bred cottage-family, is a circumstance of which their country has reason to he proud.