How did railroads impact the settlement of the west around 1864?

Under President Abraham Lincoln in 1862, the Pacific Railway Act was approved.  With most of the nation focused on the Civil War, less attention was paid to westward expansion.  In previous decades, westward expansion had been an important focus in the United States.  People traveling west had gone by covered wagon or by horse.  This way of travel was slow and was filled with obstacles.  Wagons were made of wood and could break.  Horses and oxen could become ill and die.  The journey could take from four months to over a year.
In 1869, the Transcontinental Railroad was completed.  After this, travel from the East to the West was much quicker and more efficient.  People did not have to worry about feeding livestock or repairing wagons.  Instead, they paid a fare and boarded a train to go west.  By the year 1876, one particularly fast train had a direct route from New York City to San Francisco that took about four days.  This transformed westward expansion in the United States.  New immigrants arriving in New York City could quickly and easily move west, where the population was relatively small and there were more economic opportunities.