If you are the spouse of such a deceased veteran then you should head over, too.
After the above date, the U.S. Eighth Army used Agent Orange as a defoliant in the area above the Civilian Control Line (CCL).
This agent was spread around like candy, and its use harmed thousands of veterans. It was hand sprayed and used around firing batteries and guard points.
It was used as a dust preventative on almost all the local roads above the CCL. If you drove on dusty roads then you almost certainly breathed dust containing the agent.
The list of ailments attributed to this poison is long and deadly. The above-mentioned agencies should be able to help you file your claim and research evidence of your exposure.
This is a forgotten problem. Many Korean veterans were deeply harmed, and they need to apply for help with their problems and compensation.