Polk turned a campaign into a checklist

When James K. Polk took office in 1845, he laid out a tightly defined agenda rather than presenting himself as a president who needed years to discover his priorities. He wanted Texas annexed, the Oregon boundary settled, an independent federal treasury restored, and tariffs lowered. He also sought U.S. control of California and other lands then held by Mexico.

The goals required different tools. Congress passed a lower tariff and restored the independent treasury, which kept federal funds separate from private banks. Diplomacy settled the Oregon dispute with Britain along the 49th parallel. Texas was annexed, while the effort to gain territory from Mexico led to war. The 1848 treaty ending that war transferred a vast region—including present-day California and much of the Southwest—to the United States.

Finishing the agenda had a cost

Polk’s record matched the expansionist program he had set, but its completion was not simply a tidy administrative success. The war with Mexico brought enormous territorial gains and intensified the national struggle over whether slavery would be allowed in the new lands. That conflict would outlast his presidency.

Polk had pledged to serve only one term, and he did not seek reelection in 1848. His approach made the presidency resemble a fixed-term assignment: define the objectives, use the office’s powers to pursue them, then leave. The striking consequence was that he departed after four years with his central program accomplished—and a much larger, more divided United States behind him.