irected to drive them back beyond the Rio Grande; and, although it
was desirable that he should confine himself as much as possible to
defensive measures, yet, in the event of such a repulse, he was
authorized to seize and hold possession of Matamoros and other places on
the soil of Mexico.

This resolution of our government was made the subject of grave
complaint by persons who opposed the war. The order to advance from
Corpus Christi to the Rio Grande was alleged to be an act of invasion,
and consequently, that _hostilities_ were commenced by us and not by
Mexico.

It may be pardoned if we pause awhile to consider a subject of such
vital importance. The solution of the question was placed by one party
upon the determination whether the Rio Grande was the boundary between
Texas and Mexico before the battle of San Jacinto; and, if not, whether
it has been made so since by competent authority. Up to that period it
was asserted to be a recognized fact that the Nueces was the western
boundary of Texas. Mr. John Quincy Adams, in his controversy with Don
Luis De Onis, upon the Spanish boundary question, in March, 1818;[86]
and Messieurs Pinckney and Monroe, in their argument with Cevallos at
Madrid in April, 1805,[87] claimed the Rio Grande as the true limit
between the United States and Mexico, by virtue of the ancient rights of
France and the treaties between that sovereignty and the Spanish
king.[88] It was asserted, therefore, that by the cession of Louisiana
all the rights of France over Texas, as an integral part of her
territory, accrued to us; and consequently that when the State of Texas
was united to this country it was only _re_-annexed with what were
_claimed_ to be its ancient limits. But this was not a true statement
of the controversy, for after our treaty with Spain the aspect of the
affair changed. The question then was no longer what had been the
boundary under the laws between France and Spain, or between Spain and
the United States,--but what were the limits either under the colonial
government of the Mexican viceroyalty, or under the laws of Mexico, when
she became an independent republic. It was asserted that no map or
geography existed since the establishment of the republic that did not
lay down the boundary north of the Rio Grande. The map of Texas,
compiled by Stephen H. Austin, the parent of Texan colonization,
published at Philadelphia in 1835, and setting forth all the Mexican
grants in Texas,