The Defense POW/MIA Accounting Agency (DPAA) is charged with providing the fullest possible accounting for all missing personnel to their families and the nations.  We have an obligation to our missing brothers and sisters, and DPAA provides that closure.
Take a look at this document which highlights in more detail the reason and methods in accounting for our lost.
You can also visit DPAA's website by clicking here.
You may make a donation to DPAA by mailing a check or money order to:
2300 Defense Pentagon
Washington, DC 20301-2300