Why did Andrew Jackson want Native Americans to move to the West?

In his
speech on the Indian Removal Act on December 8, 1829, Andrew Jackson argued that Native
Americans were savages whose removal would facilitate the development and strengthen the
security of the Southern states:

It will place a dense and
civilized population in large tracts of country now occupied by a few savage hunters. By opening
the whole territory between Tennessee on the north and Louisiana on the south to the settlement
of the whites it will incalculably strengthen the southwestern frontier and render the adjacent
States strong enough to repel future invasions without remote aid.

Andrew Jackson believed that such an approach was fully consistent with the general
historical evolution of the US as a whole:

What good man
would prefer a country covered with forests and ranged by a few thousand savages to our
extensive Republic, studded with cities, towns, and prosperous farms, embellished with all the
improvements which art can devise or industry execute, occupied by more than 12,000,000 happy
people, and filled with all the blessings of liberty, civilization, and religion?

He also argued that this removal was in the best interests of the
Native Americans themselves, as it would, in his view, prevent their disappearance amidst the
growing white population and allow them to maintain their way of life under the protection of
federal government west of Mississippi:

It will relieve
the whole State of Mississippi and the western part of Alabama of Indian occupancy, and enable
those States to advance rapidly in population, wealth, and power. It will separate the Indians
from immediate contact with settlements of whites; free them from the power of the States;
enable them to pursue happiness in their own way and under their own rude
institutions.

Jackson believed that the Southern states
had the sovereign right to expel the Native Americans and that the federal government had no
right to intervene; he argued that federal intervention would infringe on state
sovereignty:

For the justice of the laws passed by the
States within the scope of their reserved powers they are not responsible to this Government. As
individuals we may entertain and express our opinions of their acts, but as a Government we have
as little right to control them as we have to prescribe laws for other nations.

Andrew Jacksons military experience in the Indian Wars shaped his
racially biased views of Native Americans. He perceived them primarily as an obstacle to the
further growth of the South. As slavery spread and cotton cultivation expanded, Southern
planters demanded the remaining Native American land. Jackson hoped that by implementing the
demands of the white Southerners for the expulsion of Native American peoples, he could improve
the tense relationship between the federal government and the Southern political elites, who
were angry about the protectionist tariffs imposed on the import of manufactured
goods.

Note: You can read President Andrew Jacksons Case for the Removal Act
at mtholyoke.edu.