Polk Requests a Declaration of War Against Mexico, 11 May 1846
[Background: On May 11, 1846, President James K. Polk delivered a message
to Congress asking for "prompt action" on a declaration of
war with Mexico. Hostilities, he said, had already begun, and Congress
needed only to "recognize the existence of the war."
In the message, Polk refers to the Rio Grande as the "Del Norte,"
using the second half of the full Spanish name, the Rio Grande del
Norte. He also quotes from the report filed by General Zachary Taylor
of an engagement between a few dozen Mexican and American soldiers.
This enabled him to give Congress what he knew was the most compelling
political reason for a war: Mexico had "shed American blood upon
the American soil." Document follows:]
To the Senate and House of Representatives:
In my message at the commencement of present session I informed you
that upon the earnest appeal both of the Congress and convention of
Texas I had ordered an efficient military force to take a position
"between the Nueces and the Del Norte." This had become necessary
to meet a threatened invasion of Texas by the Mexican forces, for which
extensive military preparations had been made. The invasion was threatened
solely because Texas had determined, in accordance with a solemn resolution
of the Congress of the United States, to annex herself to our Union,
and under these circumstances it was plainly our duty to extend our
protection over her citizens and soil.
This force was concentrated at Corpus Christi, and remained there until
after I had received such information from Mexico as rendered it probable,
if not certain, that the Mexican Government would refuse to receive
our envoy.
Meantime Texas, by the final action of our Congress, had become an
integral part of our Union. The Congress of Texas, by its act of December
19, 1836, had declared the Rio del Norte to be the boundary of that
Republic. Its jurisdiction had been extended and exercised beyond the
Nueces. The country between that river and the Del Norte had been represented
in the Congress and in the convention of Texas, had thus taken part
in the act of annexation itself, and is now included within one of
our Congressional districts. Our own Congress had, moreover, with great
unanimity, by the act approved December 31, 1845, recognized the country
beyond the Nueces as a part of our territory by including it within
our own revenue system, and a revenue officer to reside within that
district has been appointed by and with the advice and consent of the
Senate. It became, therefore, of urgent necessity to provide for the
defense of that portion of our country. Accordingly, on the 13th of
January last instructions were issued to the general in command of
these troops to occupy the left bank of the Del Norte. This river,
which is the southwestern boundary of the State of Texas, is an exposed
frontier....
[In the map below, notice that the land disputed
between the US and Mexico included about half of what is now the state
of Texas as well as New Mexico.]
The Mexican forces at Matamoras assumed a belligerent attitude, and
on the 12th of April General Ampudia, then in command, notified General
Taylor to break up his camp within twenty-four hours and to retire
beyond the Nueces River, and in the event of his failure to comply
with these demands announced that arms, and arms alone, must decide
the question. But no open act of hostility was committed until the
24th of April. On that day General Arista, who had succeeded to the
command of the Mexican forces, communicated to General Taylor that
"he considered hostilities commenced and should prosecute them."
A party of dragoons of 63 men and officers were on the same day dispatched
from the American camp up the Rio del Norte, on its left bank, to ascertain
whether the Mexican troops had crossed or were preparing to cross the
river, "became engaged with a large body of these troops, and
after a short affair, in which some 16 were killed and wounded, appear
to have been surrounded and compelled to surrender."...
The cup of forbearance had been exhausted even before the recent information
from the frontier of the Del Norte. But now, after reiterated menaces,
Mexico has passed the boundary of the United States, has invaded our
territory and shed American blood upon the American soil. She has proclaimed
that hostilities have commenced, and that the two nations are now at
war.
As war exists, and, notwithstanding all our efforts to avoid it, exists
by the act of Mexico herself, we are called upon by every consideration
of duty and patriotism to vindicate with decision the honor, the rights,
and the interests of our country....
In further vindication of our rights and defense of our territory,
I invoke the prompt action of Congress to recognize the existence of
the war, and to place at the disposition of the Executive the means
of prosecuting the war with vigor, and thus hastening the restoration
of peace.