{"value"=>"<p>Spans Sprague's career from 1874-1934. Some of the earliest letters were written by Sprague to his future (second) wife Harriet Chapman Jones. However, most of the correspondence concerns his businesses and inventions. The series is arranged chronologically and, particularly in the early years, contains non-correspondence as well. It should be noted that there are also significant accumulations of correspondence outside of this series. Researchers interested in particular aspects of Sprague's career should be sure to consult this series as well as series relating to particular companies or activities. Correspondents include Sprague's co-workers and railroad and electric company officials, including Thomas Edison.</p>"}