This Geni profile for Angus McSween says that he was the son of John Angus McSween and Christian of the Highlands, Inverness-shire, Scotland; that Angus married Margaret Campbell and died at 17 Tong about 1840.
I think that the Angus who died in Tong, Ross-shire was not the son of John Angus McSween and Christian. (I'm not saying that John Angus did not have a son called Angus)
Please see the Geni profile for Angus MacSween, born c.1770, on Isle of Harris, Scotland and died c.1840 in Tong, Parish of Stornoway, Ross-shire, Scotland. He was the husband of Margaret Campbell, also from Harris.
Angus MacSween
Thank you