Zachary Taylor, Mathew B. Brady, photographer, 1849. By Popular Demand: Portraits of the Presidents and First Ladies, 1789-Present

On May 8, 1846, General Zachary Taylor defeated a detachment of the Mexican army in a two-day battle at Palo Alto and Resaca de la Palma. This victory forced Mexican troops across the Rio Grande river to Matamoros, protecting the newly annexed state of Texas from invasion. Five days later, the United States declared war against Mexico. At the direction of President James K. Polk, General Taylor led American forces on to brilliant victories at Monterrey and Buena Vista.

After a childhood on the Kentucky frontier, Taylor spent most of his adult life in the army. Widely admired for his military prowess, he was elected president on the 1848 Whig ticket. His administration was marred by improprieties on the part of cabinet members and controversies surrounding territory acquired by settlement of the Mexican-American War. Taylor died before the Compromise of 1850 resolved these issues, having served just 16 months in office.

UNION, Thomas W. Strong, engraver, 1848. American Political Prints Prints and Photographs Division Campaign poster for Democratic nominee Zachary Taylor. The victorious Mexican War general is shown mounted on a white charger. He holds a wide-brimmed straw hat. The scene is flanked by two columns entwined with banners bearing the names of Taylor's victories: Palo Alto and Resaca de la Palma on the left, and Monterey and Buena Vista on the right.

• The online exhibition Treaty of Guadalupe Hidalgo commemorates the 150th anniversary of the treaty ending the Mexican-American War. It includes on overview of the events leading up to the war and a digital image of the original treaty.

• To see more pictures of the military hero who became the nation's twelfth president, search on Zachary Taylor in Portraits of the Presidents and First Ladies, 1789-Present.

• The Robert Runyon Photograph Collection of the South Texas Border Area, a collection of over 8,000 items, is a unique visual resource documenting the Lower Rio Grande Valley during the early 1900s. A special presentation The Mexican Revolution: Conflict in Matamoros revisits Matamoros nearly seventy years after U.S. and Mexican troops skirmished there during the Mexican-American War.