1840S: Social Movements, Manifest Destiny and Westward Expansion James k. Polk and War with Mexico

The Democrats officially won back the presidency with James Polk, who was supported by the still-popular but retired Andrew Jackson.

Polk's presidency had these achievements:

• instigated, fought and won the Mexican War (also called the Mexican-American War) (ended in 1848 with the Treaty of Guadalupe-Hidalgo)

• annexed Texas (1845)

• settled a dispute with British (Canada) by establishing the northwest boundary in Oregon Treaty (1846)

• reduced tariffs

• reestablished an independent treasury (bank)

• admitted Iowa as a free state in 1846 (under the Missouri Compromise), with Iowa having the highest percentage of farmland of any State

• set off the gold rush by announcing there was gold in California (1849)

To Polk's credit, he really did what he said he would, unlike most politicians. He achieved the greatest territorial expansion of the United States (excluding the later acquisition of Alaska). Polk acquired the territory covered by the future states of Texas, California, Nevada, New Mexico, Arizona, Utah, Washington, and Oregon, and portions of Oklahoma, Colorado, Kansas, Wyoming, and Montana.

To win the Mexican War, the U.S. Army pushed far into Mexico territory. In September 1847, the United States captured Mexico City. Then Nicholas Trist, chief clerk of the Department of State and Polk's emissary to negotiate a peace treaty, began discussions with the Mexican Government just as Slidell had done the prior year Treaty of Guadalupe-Hidalgo, signing it with Mexico in Mexico City on February 2, 1848. This Treaty provided that:

• the Texas-Mexico border would be set at the Rio Grande River as Polk originally sought

• Mexico would grant to the United States about 525,000 square miles (55% of its prewar territory)

• the United States would pay Mexico $15 million

• the United States government would pay off up to $3.25 million worth of debts owed by Mexico to U.S. citizens, relieving Mexico of those obligations

Polk was unhappy with the terms of this Treaty. He wanted even more Mexican territory. But he felt he had no choice other than submit this Treaty to the U.S. Senate for ratification, which it did on March 10, 1848 by a margin of 38 to 14. The 2/3rd minimum required for ratification was 2/3rd of 52, or 35. The Treaty was ratified by a margin of only 4 votes.

In August 1846, soon after the war began, Congressman David Wilmot introduced a "rider" (unrelated amendment) to an appropriations bill stipulating that "neither slavery nor involuntary servitude shall ever exist" in any territory acquired from this war. Southern senators (especially South Carolina Senator John Calhoun) blocked this "Wilmot Proviso," but its concept was so powerful that it inspired the abolitionists all the way until (and through) the Civil War, much as the pro-life movement inspires people today. The Wilmot Proviso to stop slavery became as influential as the movement to overturn Roe v. Wade to stop abortion is today.

In addition to all of Polk's accomplishments in adding territory, he also had a habit if seeing every single visitor, no matter who he was, who came to the White House! No wonder it exhausted him. Still a young man, Polk died shortly after leaving office of an exhaustion-induced illness.