“[It would not be long] ere the whole surface of this country would be channeled for those nerves which are to diffuse, with the speed of thought, a knowledge of all this is occurring throughout the land, making, in fact, one neighborhood of the whole country.” -Samuel F. B. Morse: His Letters and Journals (1914), vol.2,85.

The above quote is referring to what 1840s American invention?

A. The cotton gin

B. The railroad

C. The telegraph

D. The steel plow