What reason did President James K. Polk give when he asked Congress to declare war against Mexico?

Answer 1

President James K. Polk asked Congress to declare war against Mexico in 1846 because he believed that Mexico had "shed American blood upon the American soil" (referring to a border skirmish between Mexican and US troops) and that Mexico had also refused to pay US citizens for damages as part of a longstanding dispute over the Texas border. Polk also wanted to achieve his goal of expanding US territory to the Pacific Ocean, which he believed would strengthen the country and fulfill the concept of Manifest Destiny.