Respuesta :
I believe that it would have to be either A or D but I am leaning more towards D because the Transcontinental Railroad made it easier for people to travel long distances
The correct answer is D) The completion of the Transcontinental Railroad in 1869.
The event that would be best to use as supporting evidence in your speech is The completion of the Transcontinental Railroad in 1869.
If you are about to give a speech to your class about the reasons why the United States rapidly formed over a dozen states in the West between 1850 and 1900, you have to pick the si¿ubject of the Transcontinental Railroad.
Do not forget to mention that The Pacific Railroad Act of 1852 assigned the Central Pacific and the Union Pacific Railroad companies the construction of the railroad that would link the East part of the United States with the Western part.