Vance, who serves as a coach, founded the group after his own struggle with PTSD. He says it helped him get out of a dark place. He now has a degree in social work. David Gilkey/NPR hide caption

itoggle caption David Gilkey/NPR

Mark Pierce enlisted in the military in 1970, served in Vietnam and retired in 2010. Years later, his two sons also joined the armed forces. Courtesy of Mark Pierce hide caption

itoggle caption Courtesy of Mark Pierce

Volunteers at the Maryland Food Bank in Baltimore sort and box food donations on a conveyor belt. The bank started working with groups like the USO in 2013 to provide food aid to families affiliated with nearby military bases. Pam Fessler/NPR hide caption

itoggle caption Pam Fessler/NPR

Bryan McDonel and his father, Mike, both served multiple tours in Iraq with the National Guard. Bryan was first prescribed painkillers before his deployment, and his dependence on medication prompted a downward spiral. Quil Lawrence/NPR hide caption

itoggle caption Quil Lawrence/NPR

A decade ago, U.S. soldiers were fighting and rebuilding in the Iraqi cities of Mosul and Tikrit. The past few weeks have seen those cities, among others, fall to the Sunni militant group ISIS. Here, a member of the Kurdish Peshmerga forces stands guard Thursday near an ISIS checkpoint in Mosul. Karim Sahib/AFP/Getty Images hide caption

itoggle caption Karim Sahib/AFP/Getty Images

Arlington National Cemetery is the final resting place for more than 400,000 men and women. Most were members of the armed forces who served in active duty — but not all. Paul J. Richards/AFP/Getty Images hide caption

itoggle caption Paul J. Richards/AFP/Getty Images

D-Day veteran Ralph Frias was a linguist and forward observer with the 19th Corps 963 Battalion and went over the Normandy cliffs in search of American paratroopers. After the fighting, he interviewed German POWs and French civilians. Amy Ta/NPR hide caption

itoggle caption Amy Ta/NPR