Vice President Joe Biden lays a wreath at the Tomb of the Unknown Soldier during the National Memorial Day Observance at Arlington National Cemetery and Washington, D.C on May 31, 2010. Vice President Joe Biden lays a wreath at the Tomb of the Unknown Soldier during the National Memorial Day Observance at Arlington National Cemetery and Washington, D.C on May 31, 2010. SHARE: Download: Full Size (4.3 MB) Tags: Photo Essays Credit: VIRIN: 589828-J-XEE66-113.jpg Photo Gallery