As the growing population began to fill up the towns and cities of the East Coast, Americans looked to move west. In this unit, students will see the new developments in transportation that helped make this happen, including the Transcontinental Railroad which carried settlers west where they found new ways of living. The Gold Rush took them to California. Students will also come to know of the negative impact of the westward movement, as the Native Americans who had lived on the land for centuries were forced to adjust, and often to move. Core Knowledge works to introduce students to difficult realities such as the Trail of Tears and the loss of great numbers of the American bison in an age appropriate manner.