The date is just a guess based on the reported date of his arrival in Canada (which some people seem to have mistaken for the date of composition of the song, though Fowke said no such thing; others have then copied the error without checking. Lesley Nelson's notes are largely wrong in this case) and his comment "thirty years that's gone". Logical, but a guess only.

Presumably his first name was Alexander. For what it's worth, the Canadian Census of 1881 records an Alexr Glendening, aged 74, Farmer, of Scottish origin, living at Egremont, Grey South, Ontario. Also, it appears that an Alexander Glendinning, aged 30, was married in 1862 at Brant, Ontario; his father's name was also Alexander Glendinning. This information from the Church of Latter-day Saints online database, which is not always accurate.