President james K. Polk campaigned on a platform of westward expansion. to what extent did he live up to the promise during his presidency?

James Knox Polk, the eleventh President of United States advocated the annexation of Oregon and Texas. He got the approval from the congress when Mexican troops killed 16 US soldiers during the aggression led by U. S. General Zachary Taylor across the disputed area to the banks of the Rio Grande in 1846 By using a combination of military threats and diplomacy, Polk managed to arrive at a compromise with England that set the 49th parallel as the Oregon Territory's northern boundary and expanded through the west.