In 1916, General John J. Pershing entered Mexico to pursue Francisco (Pancho) Villa, who had raided U.S. border areas. Pershing withdrew his forces on 5 February 1917.
Citation:
Richert, Lucas Paul. "General Pershing enters Mexico".
The Literary Encyclopedia. First published 01 November 2008
[http://www.litencyc.com/php/stopics.php?rec=true&UID=5569, accessed 22 May 2013.]