(Courtesy: U.S. Army)PHOENIX - With news that American forces have been completely withdrawn from Afghanistan, a viral photo has come to symbolize the end of America's longest war.The photo, described by officials with the 18th Airborne Corp as that of the last soldier to leave Afghanistan, has been liked over 11,000 times and retweeted over 2,700 times on Twitter."Our troops displayed grit, discipline and empathy," read a portion of the post.While the tweet did not identify the soldier, the Defense Visual Information Distribution Service (DVIDS) as well as a Facebook page belonging to the 18th Airborne Corps, identified the soldier as Major General Chris Donahue.The photo was taken as Maj.