124 a short history of the united states
When word of this engagement reached Washington, Polk immedi-
ately prepared a war message. He told Congress that Mexico had “shed
American blood on American soil,” and he asked the House and Sen-
ate to “recognize the existence of war” between the two countries. A
bill appropriating $ 10 million and authorizing the President to call for
50 , 000 volunteers prompted the protests of Whig congressmen, who
claimed they were being asked to vote on providing volunteers before
war had been declared, an act of outright aggression. To resolve the
problem the administration’s leaders in Congress attached a preamble
to the bill stating that war already existed by virtue of the invasion of
Texas by Mexico. The measure passed and the President signed it on
May 13 , 1846.
The war itself provided one military victory after another for the
United States. General Taylor defeated a superior force of Mexicans at
Buena Vista in February 1847 ; and General Winfield Scott led an expe-
Military operations during the Mexican War