Rio Norte as being the legitimate boundary
of _Louisiana_, and not of Texas. Neither they nor France had ever been
in possession of the country beyond the Sabine. Spain had always held
possession, and had divided the territory into provinces as she pleased.
One of these was called Texas, and its boundaries had been designated
and altered at her will. With these the United States had no concern. If
their claim could be sustained, it must be by proving that Louisiana
extended of right thus far. This had no connection with the boundaries
which Spain might have assigned to her province of Texas. These might
have extended beyond the Rio del Norte, or have been east of the Rio
Nueces. There is not the slightest connection between the legitimate
boundaries of Louisiana, and those of the Spanish province of Texas. The
presumed identity is a mere supposition.

It is not necessary to discuss the soundness of the pretensions to the
Rio Norte, asserted by Mr. Jefferson and Mr. Monroe, since they were
yielded in exchange of Florida and some other objects by the treaty of
1819; a treaty extremely popular at the time, and the execution of which
was pressed with great zeal and perseverance.

Whenever ultimately ceded to Mexico, that republic fixed its boundaries
as it thought proper. Texas and Cohahuila were declared to form a state;
and the Rio Nueces was, made the boundary of Texas. When Texas declared
itself independent, it was the insurrection of only part of a state; for
Cohahuila remained united to Mexico. But the Rio Nueces was the boundary
between the department of Texas and the state of Tamaulipas. The whole
contested territory lies within the limits of Tamaulipas, which never
was, under the Mexican Government, connected in any shape with Texas.

The question now under consideration is only that between the United
States and Mexico; and in that view of the subject, it is quite
immaterial whether the acts of the United States emanated from Congress,
or from the Executive. No act of either, recognizing the country beyond
the Nueces, as a part of the territory of the United States, can be
alleged against Mexico, as a proof of their right to the country thus
claimed. Any such act is only an assertion, a declaration, but not an
argument sustaining the right. It is, however, proper to observe here,
that the port of delivery west of the Nueces, erected by the act of
Congress "To establish a collection district in the state of Texas