Slight information may be gained of his connection with the Royal Highland Emigrant Regiment from the "Letter-Book" of Captain Alexander McDonald, of the same regiment. In embodying that regiment he was among the very earliest and readiest. Just why he should have exhibited so much feeling against the Americans whose country he had never seen and who had never harmed him in the least, does not appear. Captain McDonald, writing from Halifax, September 1, 1775, to Colonel Allan MacLean, says,—
"What Men that are on the Island of St. Johns (Prince Edward's) are already Engaged with Glenaladall who is now here with me, also young Mcdonald, with whom he came, he will Write to you by this opportunity and from the Contents of his Letter I will Leave you to Judge what sort of a Man he is."
By the same letter, "young Mcdonald" had been sent "to ye Island of St. John," unquestionably for the purpose of raising the Highlanders. His great zeal is revealed in a letter from Captain Alexander McDonald to Major Small, dated at Halifax, November 15, 1775:
"Mr. McDonald of Glenaladale staid behind at Newfoundland and by the Last accounts from him he and one Lt Fizgerald had Six and thirty men. I dont doubt by this time his having as many more, he is determined to make out his Number Cost what it will, and I hope you will make out a Commission in his brother Donald's name, * * * poor Glenaladall I am afraid is Lost as there is no account of him since a small Schooner Arrived which brought an account of his having Six & thirty men then and if he should Not be Lost He is unavoidably ruined in his Means."
The last reference is in a letter to Colonel Allan MacLean, dated at Halifax June 5, 1776:
"Glen a la Del is an Ornament to any Corps that he goes into and if the Regiment is not established it had been telling him 300 Guineas that he had never heard of it. On Account of his Affairs upon the Island of St. John's and in Scotland where he was preparing to go to settle his Business when he received the Proposals."
The British government offered Glenaladale the governorship of Prince Edward Island, but owing to the oath of allegiance necessary at the time, he, being a catholic, was obliged to decline the office.