IT'S A TELEGRAM
'(<a href="http://www.j-archive.com/media/2010-05-12_J_22.wmv">Sarah of the Clue Crew reports from the National Archives in Washington, D.C.</a>)  Once deciphered, the Zimmerman telegram aided U.S. entry into World War I by enraging the public; Germany promised U.S. land to this country'
Mexico