 The "Biographical Dictionary of the Nor'Westers", published as part of his "Documents Relating to the North West Company" (1934), is full of evidence of the extensive correspondence he carried on with descendants of the partners, trying to locate new letters, journals and account books.Although articles in the Dictionary of Canadian Biography have expanded knowledge of some of the Company's partners, Wallace's work remains a fundamental source.One of his most important discoveries, near the end of his active career, was the correspondence of the Company's partner Æneas Cameron, then in the possession of descendants in Scotland and now at the Hudson's Bay Company Archives in Winnipeg.