Which US region was most impacted by the completion of trans continental railroad in 1869

The West region of the United States was the most impacted by the completion of the transcontinental railroad in 1869. The railroad significantly increased transportation and communication between the east coast and the west coast, allowing for easier movement of people, goods, and ideas. It also accelerated the settlement of the West and brought about economic growth and development in the region. Additionally, the construction of the railroad displaced indigenous people and had a significant impact on their way of life.