The Mexican War

Tensions in Texas boiled over in April 1846, and within weeks reports reached Washington that Mexican troops had ambushed American dragoons. President James Polk, an expansionist who had his eye on California, quickly implored Congress to declare war, which it did on May 13.

Most of the country gleefully went along, although there were some dissenters, including a young and obscure congressman named Abraham Lincoln, and an equally obscure writer, Henry David Thoreau.

When American forces invaded Mexico, victories followed. General Zachary Taylor became a national hero, and would soon occupy the White House. And when the final peace treaty was signed in 1848, the United States owned California and the southwest.

The Mexican War isn't well remembered today. But when Grant and Lee met at Appomattox in 1865, the two generals, who had been young officers in Mexico, had a pleasant conversation about it.

Image: General Zachary Taylor, courtesy Library of Congress