Our well-founded claim, grounded on continuity, has greatly strengthened, during the same period, by the rapid advance of our population toward the territory — its great increase, especially in the valley of the Mississippi — as well as the greatly increased facility of passing to the territory by more accessible routes, and the far stronger and rapidly-swelling tide of population that has recently commenced flowing into it.

Letter to Richard Pakenham, British minister to the United States, concerning the boundary dispute between the two countries (3 September 1844) - Letter to Richard Pakenham (September 1844)