Mo. Rev. Stat. § 9.070

April ninth of every year shall be known and designated as "Prisoners of War Remembrance Day". It shall be a day on which to commemorate the sacrifices of those persons who suffered captivity in foreign lands while in the service of their country. The teachers and students of the schools of this state shall observe the day with appropriate exercises. All citizens of this state are requested to devote some portion of prisoners of war remembrance day to solemn contemplation on the plight of the men and women of this country who have been held prisoners of war.