Manifest Destiny: The belief held by Americans in the 19th century that it was their destiny to expand across the continent from east to west. This concept served as a precursor to policies used during westward expansion.
Indian Removal Act: A law passed in 1830 under President Andrew Jackson which forcibly relocated Native American tribes from their ancestral lands to make way for white settlers. It can be seen as a precursor to later policies aimed at removing Native Americans from their territories during westward expansion.
Homestead Act: An act passed in 1862 which provided free land in the western territories to anyone willing to settle and improve it. This act encouraged migration and settlement, serving as another precursor to policies used during westward expansion.