further thoughts on Glengarry:

The Loyalists who established themselves in Upper Canada came from the south.
Many of them made their way from the Mohawk Valley, west of Albany on the Hudson River, where they had settled on land originally acquired by Sir William Johnson. Some were veterans of the French and Indian Wars. Johnson also brought in Highlanders from Inverness-shire and the west of Scotland in an effort to populate the very large territory he had acquired. A group of around 400, led by the tacksmen brothers Allan, Alexander and John MacDonell, sailed in August 1773 on the Pearl from Fort William at the head of Loch Linnhe to New York. There was an outbreak of smallpox on board, and twenty-five children died on the voyage. These were Catholic families, traditionally Jacobite supporters, who saw little future for themselves in Scotland. Their disillusion with Highland landlords at home may have contributed to their adherence to King George when the Thirteen Colonies rebelled. The Mohawk Valley, like other Highland communities in America, responded to the call for recruits for King George's American regiments.

Scotland's Glengarry lies north of Fort William, reaching west towards Knoydart, still one of the most wild and remote parts of the West Highlands. It was MacDonell country. When in 1784 the Mohawk Valley people made their way north they took the name with them, and where they settled along the upper St Lawrence River became Glengarry County. The Loyalist settlers were joined over the next few decades by friends and family, as Highland emigration intensified. They arrived in 1785 and 1786, the latter group a substantial migration of families evicted from Knoydart to make way for sheep. Upper Canada, they believed, would enable them to maintain a traditional Gaelic community. As was recognized at the time, this was not an isolated event. 'These people, when once they settle in Canada, will encourage others, as they are now encouraged by some friends before them. They will form a chain of emigration.' This is exactly what happened. More came in 1790. As the struggle for survival in Scotland's Glengarry intensified, a local priest, Alexander MacDonell, encouraged migration to factory jobs in Glasgow. When this source of livelihood also failed he came up with the idea of the Glengarry Fencibles (fencible regiments were raised to defend home territory), which saw service in Ireland, a
Catholic regiment in action against Catholic Irish dissidents. In 1802 it was disbanded, leaving the men with no means of support. Alexander MacDonell conceived of a plan to enable them to emigrate to Upper Canada. He raised money from landowners and industrialists to pay their passage: 800 joined the Glengarry settlement. By 1806 there were over 10,000 Catholic Highlanders from Scotland's Glengarry area in Canada's Glengarry, and the exodus continued. 'Go not to Glengarry, if you're not a Highlandman,' commented John MacTaggart in an 1829 guide.
-- Jenni Calder. Scots in Canada. Edinburgh Scotland: Luath Press Limited, 2003