A 1996 state law designated December 7 as Pearl Harbor Remembrance Day.
All flags, at state and local government buildings, were flown at half-staff to honor those who died or were wounded during the attack on Pearl Harbor, Hawaii, 72 years ago.
More than 2,000 members of the U.S. Military died in the attack.
"Pearl Harbor Remembrance Day reminds us of the sacrifices that have been made by our men and women in uniform, and of their tremendous courage through the generations," said Gov. Jay Nixon. "When Missourians see the flags at half-staff on Saturday, I ask that they remember and honor those who have served or who are now serving our nation."