The correct answers are:
- There was plenty of cheap land;
- Peace had been made with the Indians;
The westwards migration and settlement was triggered by few things, like the cheap land, peace with the Indians (well, with most of them), and government motivation and actions.
The government wanted to make people move westwards so that they can get hold of more territory, and they lured people by giving them land for free and land for very low amount of money, and we are talking about very big peaces of land. The people embraced the opportunity to become big landowners and they rushed to settle in the west in order to get the biggest and best pieces of land. Also, a major factor was the safety, and once there was peace with most of the Indian tribes, it was safe enough to move there and not be worried about getting killed.
