[Sidenote: Defect in the southern boundary of the United States before 1819.]
In the second decade of this century, and down to the latter part of it, the United States had not acquired the territory of the country as far as to the natural southern boundary east of Louisiana. This boundary was, of course, the Gulf of Mexico; but Spain held in quasi possession a broad strip, and then a long peninsula, of land along and within this boundary. In other words, the territory called Florida, or the Floridas, was, politically, a colony of Spain, but geographically a part of the United States. It was inhabited chiefly by Indian tribes. Spanish rule in this territory was, therefore, foreign rule, both from the geographical point of view and the ethnical. Indian rule was not to be thought of in the nineteenth century. There was but one natural solution of the question. It was that the United States should annex this territory and extend the jurisdiction of the general Government over it.
The Treaty of Paris of 1763 was the first great { 21} international agreement which gave a fair degree of definiteness to the claims of England, France, and Spain, upon the North American continent. In this Treaty, France surrendered Canada, Cape Breton, and all claims to territory east of the Mississippi River, from the source of the river to the point of confluence of the Iberville with it, to Great Britain. From this latter point, the boundary between the two powers was declared to be the middle line of the Iberville, and of the Lakes Maurepas and Pontchartrain, to the Gulf of Mexico. It is also expressly stated in this Treaty that France cedes the river and port of Mobile to Great Britain.
In this same instrument, Spain surrendered to Great Britain Florida and every claim to territory east and southeast of the Mississippi.
[Sidenote: The boundary between Louisiana and Florida.]
The boundary between Louisiana and Florida had, to that time, been the River Perdido. After the cessions above mentioned to Great Britain, the British Government united the part of Louisiana received from France with Florida, and then divided Florida into two districts by the line of the River Appalachicola. That part lying to the west of this river was named West Florida, and the part east of it was called East Florida.