Tesla's Time Travelers

American history teacher Nathan Greene looked at his bulletin board. How did Benedict Arnold become the second president of the United States? And who the heck was Shippen Jefferson? Where were John Adams and John Quincy Adams? Shaken, Greene pulled down his map of the United States. He scanned the map: no major changes."Mr. Greene," Victor Bridges called out. "Tennessee is missing!'Greene's jaw dropped. Where Tennessee had once proudly been, there was now "Franklin."Had Greene and his high school students inadvertently changed history with their field trip to the Philadelphia of 1776? There had been no such repercussions the previous spring when Greene took his class to Ford's Theater for the fateful performance of "Our American Cousin" at Ford's Theater on the evening of April 14, 1865. That spring trip had been such a success that his students fell in love with history and begged for another trip for their junior year.But somehow the Philadelphia field trip had...