Answer :
If you were giving a speech to your class about reasons why the
United States rapidly formed over a dozen states in the West between
1850 and 1900, you would want to focus on the Transcontinental Railroad in 1869, which revolutionized travel to the West.
The correct answer is D) completion of the Transcontinental Railroad in 1869.
The event that would be best used as supporting evidence in your speech is the completion of the Transcontinental Railroad in 1869.
The Pacific Railroad Act of 1862 authorized two companies to connect the East and the West of the United States through the railroad: the Union Pacific and the Central Pacific. They started works in Omaha, Nebraska, to the west, and in Sacramento, California, to the east. On May 10, 1969, the met at Promontory, Utah, and the deed was done.