President Polk was a native of North Carolina. In boyhood he removed with his father to Tennessee, and in 1839 rose to the position of governor of that State. At the head of his cabinet he placed James Buchanan of Pennsylvania. [Sidenote: Causes of Mexican War.] 2. A war with Mexico was at hand. On the 4th of July, 1845, the Texan legislature ratified the act of annexation. The Mexican minister at Washington immediately left the country. The authorities of Texas sent an urgent request to the President to dispatch an army for their protection. Accordingly, General Zachary Taylor was ordered to march thither from Louisiana. Texas claimed the Rio Grande as her western limit, while Mexico was determined to have the Nueces as the separating line. The government of the United States resolved to support the claim of Texas. General Taylor was sent to the mouth of the Nueces, and in January, 1846, he moved forward to the mouth of the Rio Grande, and built Fort Brown. [Illustration: James K. Polk.] [Sidenote: Palo Alto and Resaca de la Palma.] 3. On the 26th of April a company of American dragoons was attacked by the Mexicans, _east of the Rio Grande_, and was obliged to surrender. This was the first bloodshed of the war. General Taylor hastened to Point Isabel and strengthened the defenses. This done, he set out with a provision-train and an army of two thousand men to return to Fort Brown. Meanwhile, the Mexicans had crossed the Rio Grande and taken a position at Palo Alto. On the 8th of May the Americans came in sight and joined battle. After a severe engagement the Mexicans were driven from the field. 4. On the following day General Taylor resumed his march, and came upon the Mexicans again at a place called Resaca de la Palma. Here the enemy fought better than on the previous day. The American lines were severely galled until Captain May's dragoons charged through a storm of grape-shot, rode over the Mexican batteries, and captured La Vega, the commanding general. The Mexicans, abandoning their guns, fled in a general rout. [Sidenote: War Declared.] 5. When the news from the Rio Grande was borne through the Union, the war spirit was everywhere aroused. On the 11th of May, 1846, Congress made a declaration of war. The President was authorized to accept fifty thousand volunteers, and ten million dollars was placed at his disposal. Nearly three hundred thousand men rushed forward to enter the ranks. 6. The American forces were organized in three divisions: THE ARMY OF THE WEST, under General Kearny, to cross the Rocky Mountains against the northern Mexican provinces; THE ARMY OF THE CENTER, under General Scott as commander-in-chief, to march from the Gulf coast into the heart of the enemy's country; THE ARMY OF OCCUPATION, under General Taylor, to hold the districts on the Rio Grande. [Sidenote: Monterey.]