U.S. service members attend the POW/MIA 24-hour Recognition Run closing ceremony at Memorial Park on Joint Base Langley-Eustis, Virginia, Sept. 21, 2018. As of Aug. 29, 2018, the number of Americans missing and unaccounted for from the Vietnam War is 1,594. (U.S. Air Force photo by Airman 1st Class Anthony Nin Leclerec)