Thomas Potter Macqueen was born at Segenhoe Manor, Ridgmont, Bedfordshire in 1791 son of Malcolm and Marianne (Potter) Macqueen.
He devised a plan to develop the Australian colony with settlers with sufficient capital to employ convicts on their own account. In 1823 he obtained a grant of 10,000 acres from Governor Sir Thomas Brisbane with a provisional reserve of a further 10,000 acres.
Potter Macqueen remained in England until 1834. Meanwhile he appointed Peter McIntyre as overseer and to be responsible for the development of Segenhoe.
Mechanics, farmers and shepherds, equipped with farm machinery, stores, sheep, horses and stud cattle were dispatched in two chartered ships, Hugh Crawford and Nimrod, arriving in Sydney on 7 April 1825. 
Sir William Edward Parry visited Segenhoe in March 1832. He arrived on a Monday morning having been driven over by Captain Dumaresq of 'St. Aubins'. Parry had heard much of Segenhoe estate and was eager to see it; he wasn't disappointed and found it 'most excellent and desirable' with fine well watered land and good natural boundaries. No expense had been spared on the roads in that area and Parry thought they were equal to and much resembling the roads in a gentleman's park in England. He was very impressed and preferred it to any estate he had seen so far in the Colony.
Sir W.E. Parry was was received by Mr. Sempill's wife and sister, Mr. Sempill being absent at the time. Sempill's wife Susannah Sempill was a sister of John Dow who in later years was employed as a superintendent at Sempill's 'Belltrees'. Her sister with her at Segenhoe that day was Agnes Dow who later married James Busby.
Parry had met with H.C. Sempill previously in a chance meeting in Sydney in January 1831 that changed the future of the Australian Agricultural Company. At the meeting Sempill offered to sell on behalf of Potter MacQueen, a threshing machine. In the course of conversation he informed Parry of excellent quality of land on the Liverpool Plains that could be used for sheep breeding. They went immediately to the Surveyor General's office to inspect maps which convinced Parry to arrange for the exchange of the company's coastal land for land at Warrah and Goonoo Goonoo on the Liverpool Plains.
There were numerous assigned servants at Segenhoe including:
William Powell and John Taff who arrived on the 'Portland',
Henry Hall a glass cutter from Warwick arrived on the Asia in 1832
Dominick Herkins a soldier and labourer who had been convicted in Jamaica, arrived on the Asia in 1832
Charles Bevan carpenter and joiner who arrived on the Adrian in 1830.
There was also a hospital on the estate. John Macredie was employed as surgeon there in 1833 and John McLeod Gillies was employed as a hospital assistant.
John Portus and Benjamin Lee were indented servants. Benjamin Lee arrived on the Thames in 1829. He was sent by Macqueen from England to be assistant Superintendent at Segenhoe under orders of Peter McIntyre, Macqueen's agent. Although under employment contract, he waited many months for wages, eventually instigating court proceedings to recover funds owing to him.
John Portus was a millwright and arrived on the Hugh Crawford in 1825. He became well known throughout the district and constructed a steam mill in 1840 known as Morpeth Wheat Mills.
Arrival of Macqueen in Australia
By 1833, Macqueen's wife Anne Astley had passed away and in 1834 Macqueen sold his English estate to the Duke of Bedford and sailed to New South Wales himself. He arrived in Hobart on the Bardaster in June 1834.
H.C. Sempill and his family occupied the main homestead at Segenhoe until 1834 when Macqueen arrived. The Sempills then moved to other accommodation, first living in a smaller unsatisfactory building and then later building a permanent home at Belltrees. H.C. Sempill had acquired much land on his own behalf since his arrival - Ardenhall, Huntingdon and Aberfoyle among them and also the beautiful 'Belltrees.' In the 1840's Sempill ran into financial difficulties. He sold his properties and returned to Scotland where he remained.
Thomas Potter Macqueen became known for his extravagance at the Segenhoe estate. It was rumoured that his mistress was Madame Ramus who married Thomas Hollingworth Fowler, a former superintendent on Macqueen's estate.