The American Electromagnetic Telegraph with Reports to Congress and a Description of All Telegraphs Known to Science Employing Electricity or Galvanism by Alfred Weil is a very valuable source of information on the history of telegraphy in the United States. The book details how electromagnetic telegraphs work, reports to Congress on the matter, and reviews all telegraph systems that used electricity or galvanism at the time. This book offers the reader a deep understanding of the technological advances in telecommunications in the 19th century.