Andy Soule, a U.S. Army veteran, lost both his legs to a bomb in Afghanistan in 2005. Four years ago, he won America's first medal — Olympic or Paralympic — in the biathlon event. David Gilkey/NPR hide caption

itoggle caption David Gilkey/NPR

Former Marine Josh Sweeney lost both of his legs to a bomb in Afghanistan in 2009. He's competing with the U.S. Men's Sled Hockey team at the Paralympics in Sochi. David Gilkey/NPR hide caption

itoggle caption David Gilkey/NPR

A U.S. Army soldier guards the remains of a burned-out military ammunition truck after it was attacked in Fallujah, Iraq, on Oct. 19, 2003. Fallujah and its surrounds were the site of some of the bloodiest fighting for U.S. troops during the Iraq war. Khalid Mohammed/AP hide caption

itoggle caption Khalid Mohammed/AP

Hal Faulkner (left), 79, receives his new papers from two Marines after having his military status changed to "honorable discharge" at a recent ceremony. Faulkner was kicked out of the Marine Corps in 1956 for being gay. Courtesy of Phil Latzman hide caption

itoggle caption Courtesy of Phil Latzman

Michael Hartnett was a Marine during the Gulf War and served in Somalia. He received a bad conduct discharge for abusing drugs and alcohol. His wife, Molly, helped him turn his life around. Quil Lawrence/NPR hide caption

itoggle caption Quil Lawrence/NPR