<Li> Knopf, Alfred A. (1952), Keenlyside, Hugh LL.; Brown, Gerald S., eds., Canada and the United States: Some Aspects of Their Historical Relations, Alfred A. Knopf </Li> <Li> Longstaff, F.V.; Lamb, W.K. (1945), "The Royal Navy on the Northwest Coast, 1813 - 1850 . Part 1 ." (PDF), The British Columbia Historical Quarterly, 9 (1): 1--24 </Li> <Li> Longstaff, F.V.; Lamb, W.K. (1945), "The Royal Navy on the Northwest Coast, 1813 - 1850 . Part 2 ." (PDF), The British Columbia Historical Quarterly, 9 (2): 113--128 </Li> <Li> Mackie, Richard Somerset (1997), Trading Beyond the Mountains: The British Fur Trade on the Pacific 1793--1843, Vancouver, B.C.: University of British Columbia Press </Li>

The slogan fifty-four forty or fight referred to the northern limit of disputed california territory