What were James K. Polks contributions to America?

Answer 1

As a result of winning the Mexican War, California, New Mexico and Arizona,as well as parts North, were added to the union and the border between Texas and Mexico was firmed up and secured. He also settled with a treaty with Britain, a dispute over the Northern border of the Oregon territory.

Answer 2

As a result of winning the Mexican War, California, New Mexico and Arizona,as well as parts North, were added to the union and the border between Texas and Mexico was firmed up and secured. He also settled with a treaty with Britain, a dispute over the Northern border of the Oregon territory.