After his return he ascended the Peace River, crossed the Rocky Mountains, and on a rock on the shore of the Pacific Ocean in British Columbia, inscribed with vermillion and grease, in large letters, "Alexander Mackenzie, from Canada, by land, the Twenty-second of July, One Thousand Seven Hundred and Ninety-three." That was his record as the first white man to cross North America, north of Mexico.

A few years afterwards he received the honor of knighthood for his discoveries.

He gained much distinction as a leader, though the great McTavish in his Company was never very friendly to him.
At length he retired, became a representative in the legislature of Lower Canada, and was for a time a travelling companion of the Duke of Kent.

With a desire for loftier station, he settled in his native land, married the beautiful and gifted daughter of the House of Seaforth, and from her enjoyed the property of Avoch, near Inverness.
Three years before the starting of Lord Selkirk's Colonists and before his marriage with Geddes Mackenzie, Sir Alexander took up his abode in Scotland.

He was the guardian of the rights of the North-West Company and manfully he stood for them.
Mackenzie was startled when he heard in 1810 of Lord Selkirk's scheme to send his Colonists to Red River.