An aristocrat from Scottish high society, Thomas Douglas became, following his father's death in 1799, the 5th Earl of Selkirk and heir to the family fortune. He studied law and the humanities at the University of Edinburgh. In 1792, at the age of 21, he travelled in the Scottish Highlands, where he was shocked by the plight of many landless Scottish farmers. As a result, he began to think up ways of encouraging immigration to the British colonies. He developed two proposals for settlement in British North America, one at Sault-Sainte-Marie, Ontario, the other on
Prince Edward Island. The Ontario settlement never got off the ground, but in 1803 ships carrying Scottish immigrants arrived on Prince Edward Island.
In 1805 Selkirk wrote a book entitled Observations on the present state of the Highlands of Scotland, with a view of the causes and probable consequences of emigration. Despite criticism from the British Colonial Office and the Royal Highland and Agricultural Society of Scotland, the book met with great success and made Selkirk a celebrity. In 1806 Selkirk was appointed to the House of Lords, where he represented Scotland. In 1807 he was named Lord-Lieutenant of Kirkcudbright District in Scotland, was elected a fellow of the Royal Society of London and became a member of the Alfred Club of London.
Travelling throughout North America, between Halifax, Boston, Montréal and Toronto, in 1808 Thomas Douglas revisited a proposal he had made six years earlier to establish a colony in the Red River valley. In 1811 Selkirk signed an agreement with the financially troubled Hudson's Bay Company (HBC), owner of the territory. In exchange for the establishment of a colony in the region, the HBC sold Selkirk 116,000 square miles of land for ten shillings. By the end of the summer of 1812, the first settlers began arriving in the new colony.
Selkirk spent the better part of his life in the administration and defence of his Red River colony. Many clashes with the Nor-Westers, adversaries of the Hudson's Bay Company, caused him to spend most of his later years defending his actions before the courts.
- Gray, John Morgan. "Thomas Douglas". Dictionnaire biographique du Canada. vol. V. [Québec] : Presses de l'Université Laval, 1983. P. 289-295