Final answer:
James Polk campaigned to acquire the entire Oregon Territory but accepted the 49th parallel as a compromise to avoid conflict and prepare for other expansion efforts.
Step-by-step explanation:
President James Polk advocated for acquiring the entire Oregon Territory with the slogan "Fifty-four forty or fight!" Nevertheless, he was willing to compromise and instead accepted a boundary along the 49th parallel, peacefully dividing the region between the United States and Britain. This strategic move allowed for the consolidation of the Puget Sound deepwater port and laid the groundwork for future westward expansion while avoiding conflict with Britain and preparing for confrontation with Mexico.