After sundry informal communications with the British minister upon the subject of the claims of the two countries to territory west of the Rocky Mountains, so little probability was found to exist of coming to any agreement on that subject at present that it was not thought expedient to make it one of the subjects of formal negotiation to be entered upon between this Government and the British minister as part of his duties under his special mission.

By the treaty of 1783 the line of division along the rivers and lakes from the place where the forty-fifth parallel of north latitude strikes the St. Lawrence to the outlet of Lake Superior is invariably to be drawn through the middle of such waters, and not through the middle of their main channels.  Such a line, if extended according to the literal terms of the treaty, would, it is obvious, occasionally intersect islands.  The manner in which the commissioners of the two Governments dealt with this difficult subject may be seen in their reports.  But where the line thus following the middle of the river or water course did not meet with islands, yet it was liable sometimes to leave the only practicable navigable channel altogether on one side.  The treaty made no provision for the common use of the waters by the citizens and subjects of both countries.

It has happened, therefore, in a few instances that the use of the river in particular places would be greatly diminished to one party or the other if in fact there was not a choice in the use of channels and passages.  Thus at the Long Sault, in the St. Lawrence—­a dangerous passage, practicable only for boats—­the only safe run is between the Long Sault Islands and Barnharts Island (all which belong to the United States) on one side and the American shore on the other.  On the other hand, by far the best passage for vessels of any depth of water from Lake Erie into the Detroit River is between Bois Blanc, a British island, and the Canadian shore.  So again, there are several channels or passages, of different degrees of facility and usefulness, between the several islands in the river St. Clair at or near its entry into the lake of that name.  In these three cases the treaty provides that all the several passages and channels shall be free and open to the use of the citizens and subjects of both parties.

The treaty obligations subsisting between the two countries for the suppression of the African slave trade and the complaints made to this Government within the last three or four years, many of them but too well founded, of the visitation, seizure, and detention of American vessels on that coast by British cruisers could not but form a delicate and highly important part of the negotiations which have now been held.