Transcontinental railroad offect us by

The goal of the transcontinental railroad was to connect the eastern part of the United States to the western part. Both the Central Pacific and the Union Pacific Railroad companies worked to build this long railroad. Some positive effects of the transcontinental railroad included more efficient transportation from coast to coast, a faster spreading of ideas throughout the United States, and increases in global and intercontinental trade. A negative effect of the transcontinental railroad was that racial tensions among Native Americans and other groups arose. 

Dpolitical is the answer