United States History Student Edition

Samuel Morse's improvements to the electric telegraph machine greatly advanced long-distance communications. Messages were sent by tapping the machine's key using Morse code, a series of dots and dashes that represent the letters of the alphabet. Science and Technology

» In 1847, scientist Maria Mitchell discovered a previously unknown comet while looking through a telescope in Nantucket, Massachusetts. She later became a professor of astronomy at the newly founded Vassar Female College.

Growth of the Railroads Americans loved their railroads in spite of irregular schedules, frequent breakdowns, and the showers of sparks that flew from the locomotives. Built in 1831, the DeWitt Clinton was the first passenger train that offered regular service in New York.

(tr)Volgi archive/Alamy Stock Photo; (cl)Ioana Martalogu/Alamy Stock Photo; (cr)Villorejo/Alamy; (b)Henry Guttmann Collection/Hulton Archive/Getty Images

GO ONLINE

357

Explore the Student Edition eBook and find interactive maps, time lines, and tools.