Read the excerpt from a magazine article written by James Gamble in 1881 and answer the question. With it disappeared the feeling of isolation the inhabitants of the Pacific Coast had labored under. San Francisco was in instant communication with New York, and the other great cities of the Atlantic seaboard. The change was a great one, but it was one to which the people readily adapted themselves to, having wished and waited so long for it. In that moment California was brought within the circle of the sisterhood of States. No longer as one beyond the pale of civilization, but, with renewed assurances of peace and prosperity, she was linked in electrical bonds to the great national family union.
What was the author referring to?
A
the completion of the Erie Canal

B
the completion of the Panama Canal

C
the completion of a transcontinental railroad

D
the completion of a transcontinental telegraph