[4][5] The successors of the Northwestern Bell Telephone were US West (which in turn was replaced with Qwest in 2000 and later under CenturyLink Communications eleven years after that).

The earliest record of telephones in the Northwestern Bell service area was a two-telephone intercom circuit used by a Little Falls, Minnesota, druggist and his clerk in 1876.

A Bell-licensed exchange is believed to have opened in Deadwood, South Dakota, between March and August 1878, just two years after Alexander Graham Bell invented the telephone, and several months before President Rutherford B. Hayes could use his phone in a little wooden booth outside of his office in the White House.

The earliest documented telephone exchange in Northwestern Bell territory was opened by Western Union in Keokuk, Iowa, on September 1, 1878.

Using superior equipment designed by Thomas Edison and Elisha Gray, Western Union was in a competitive shoot-out with the local licensees of the National Bell Telephone Company of Boston.