12. It is but fifteen years since the first line ... was constructed in
this country and at the present time there are not less than
50,000 miles in successful operation on this continent, having
over 1,400 stations, and employing upwards of 10,000 operators
and clerks. The number of messages passing over all the lines in
this country annually is estimated at upwards of 5,000,000,
producing a revenue of $2,000,000. ...
-Atlantic Monthly, March 1860
The invention discussed in this article led directly to -