1890: "stop sign" invented in Saugatuck, Connecticut 1903: Mary Anderson patents the "windshield wiper" 1904: automatic transmission invented in Boston, Massachusetts 1911: electric starter motors replace hand-cranks on automobile engines 1912: electric traffic lights invented in Salt Lake City, UT Which sector of the American economy was affected MOST by these inventions? A) agriculture B) communication C) manufacturing D) transportation