Dir. Peter Schnal. PBS, 2013. DVD. This documentary focuses on Lincoln's perspective of the Battle of Gettysburg and his Gettysburg Address. The beginning of the documentary shows how he received telegrams from the front and how he used the telegraph to communicate information about the war to his generals. The documentary is reliable because it was published by PBS, a well-known non-profit television channel that offers educational programs. The documentary was helpful because it showed me how Lincoln could use the telegraph to provide important information and make decisions from behind a desk. I used the information to support my argument that the telegraph left a legacy of improved communication for warfare and accelerated the pace of wars. Wheeler, Tom. Mr. Lincoln's Emails: The Untold Story of How Abraham Lincoln Used the Telegraph to Win the Civil War. New York: Collins, 2006. Print. This book by Tom Wheeler was written on the topic of Abraham Lincoln's use of the telegraph during the Civil War. The book included primary source telegraphs from the Civil War. The book contains reliable information because the author has created a bibliography so that the reader can make sure that the information in the book is reliable and