In November 1870 the late Dr. Mill, then senior magistrate of Thurso, received a letter from the Secretary of the Western Reserve Historical Society, Cleveland, Ohio, asking information regarding the early life and parentage of Arthur St. Clair, described as a distinguished American officer, who died in 1818, and for whose biography the Society was collecting materials. The Secretary stated that the General was born at Thurso in 1734, that he went to America in 1754 or 1755 with Admiral Boscawen, that he joined the army in one or other of these years, that "he was the second son of his father, and had received a good education, and was believed to have studied medicine, but had abandoned it". He was further said to have corresponded with relatives, including the late Sir John Sinclair of Ulbster, in Thurso and Edinburgh.
From a copy of the New York Daily Tribune, of 28th April last, we observe that under the title of "The St. Clair Papers", a memorial of the General, in two volumes, has been published containing lengthened notices of his services, and of the stirring events in which he was engaged in America from 1755 to 1763; in the American Revolution, an in the Indian wars of the South-west.
In regard to the General's birthplace and early history, the Tribune states that he was "born of a noble family in the town of Thurso, Caithness, Scotland, in the year 1734 .. He studied at the University of Edinburgh as a preparation for professional life, and was indentured to the famous physician, William Hunter of London. But he had inherited the martial temper of his race, and at twenty-three he abandoned medicine for an ensign's commission in the Royal Regiment of Foot".
On receipt of the communication to Dr. Mill in 1870, referred to, an endeavour was made to trace the General's family in Caithness. In searching the Kirk Session books of Thurso, the register of baptisms does not record any Arthur Sinclair in 1734; but on 24th March 1736 there is the following entry: "William Sinclair, merchant in town, had his son Arthur (who was born about five o'clock in the afternoon of the preceding day) baptized by the Rev. Mr. William Innes, minister here".
At this period there was in Thurso William Sinclair, merchant, a grandson of James Sinclair, second laird of Assery, whose father, John, first of Assery, was a son of Sir James Sinclair of Murkle, of the Caithness family. Possibly, then, General St. Clair may have been the son of William Sinclair, merchant in Thurso. Admiral Boscawen sailed for America in 1758, and if the General accompanied him, as he is said to have done, and. was born in 1736, he would be then about twenty-two years of age, and the Tribune states his age to have been twenty-three when he got his commission.
If General St. Clair was, as is supposed above, of the family of Sinclairs of Assery, there would be relationship with Sir John Sinclair of Ulbster, although very distant, by the marriage of George Sinclair of Assery, the General's grand-uncle, to a lady of the Ulbster family.
The following extracts are from the article in the Tribune above referred to: -
"He was with Amherst at Louisburg, where he won by his gallantry promotion to the rank of lieutenant, and under Wolfe the following year he carried the British colours on the Plains of Abraham. After the siege of Quebec he married a daughter of the Bayards of .Boston, who brought him a dowry of £14,000 inherited from her maternal grandfather, James Bowdoin. In 1764 he removed with his young wife to a fine landed estate in the picturesque Ligonier Valley of Western Pennsylvania, where several Scotch families of consequence had already settled. Here he :filled a number of prominent civil positions, and took an active part in the boundary disputes between Pennsylvania and Virginia. A man like St. Clair, with a military reputation and distinguished in civil life, could not long remain in obscurity as the spirit of resistance against the mother country gathered head in the colonies, and in December 1775 he resigned his civil offices, took leave of his wife and children, and as the event proved, of his fortune, and repaired to Philadelphia on a summons from President Hancock. In January he raised a regiment, and in May he reached Quebec at a critical time, and covered the retreat of the imperilled army. Through the disastrous days which followed Colonel St. Clair rendered efficient service until the wearied, weakened, plague-smitten and demoralised forces were brought into camp on the banks of Lake Champlain. On the 9th of August 1776 St. Clair was made a Brigadier-General by Congress, and later in the year was ordered to leave the Northern Department and join Washington in the Jerseys. During the trials and hardships of the dark winter which followed, when the genius of Washington shone out so brightly at last, St. Clair was one of the faithful and trusted advisers of the Commander-in-chief, and took a conspicuous part in the operations which were crowned with triumph at Trenton and Princeton. It was in recognition of his distinguished services in this campaign that he was commissioned a Major-General in February, and assigned once more to command in the North. On the 12th of June he took command of Ticonderoga, and was subjected to much cruel censure for abandoning that post twenty-four days later, when his works were commanded by the guns of the enemy nearly 8000 strong, against less than half that number of his own ill equipped and worse armed troops. The skilful retreat from Ticonderoga was followed as a natural sequence by the decisive victory at Saratoga, and St. Olair, although suspended for a time from command, became a member of Washington's military family. He participated in the battle of Brandywine, shared the sufferings at Valley Forge, was a member of the court martial which tried Andre, and the closing days of the war found him marching to the support of Greene in South Carolina. Equally efficient in civil and military life, he was elected President of Congress and Governor of the North-western Territory, a post which he held for fourteen years, and under his administrative control the broad foundations of coming States were securely laid and established in the freedom and education guaranteed by the great charter. He was removed in 1802 by President Madison, and returned to Pennsylvania in his old age, to find his fortunes wasted, while the Government which he had served pleaded the statute of limitations to escape reimbursing him for money advanced to prevent Washington's army from melting away. He had become responsible while administering Indian affairs for certain supplies, and this amount was also refused, at first on the ground of an informality in his accounts, and when this was rectified, the - statute was pleaded once more. His property, a valuable one for those times, was finally forced to a sale, and the old soldier and his family were - reduced to want. In a log house on a bleak ridge by the side of the old State road from Bedford to Pittsburg, and almost in sight of the broad acres which once were his, Lewis Cass found him at the age of fourscore supporting his family by selling "supplies" to the wagoners who travelled that highway. One day in August 1818, when eighty-four years old, he was discovered, lying insensible by the side of a rough and lonely road, where he had fallen from his wagon while on the way to a neighbouring town to procure some flour and other necessaries. He never rallied from the shock, and died on the "last day of summer".