Civil War Rosters-Missouri
The Civil War Archive; Union Regiments -- Missouri
Korean Conflict Casualty List
WW1 Draft Registration Cards 1917-1918 In 1917 and 1918, approximately 24 million men living in the US completed a World War I draft registration card. These registration cards represent approximately 98% of the men under the age of 46
Missouri Civil War Pension Applications a part of the USGenWeb Archives Pensions Project
Soldiers' Records: War of 1812 & WW1- searchable database at Missouri State Archives
The Missouri Mormon War  searchable database at Missouri State Archives
USIGS Military Collection- Civil War links to surname databases: Missouri
Vietnam Conflict Casualty List
23rd MO Volunteer Infantry (Union) Homepage

Additional Resources

Missouri Obituaries enter your Missouri ancestor's name to instantly search the world's largest newspaper archive; over 12 million newspaper pages
Missouri Birth Records
Missouri Marriage Records
Missouri Divorce Records
Missouri Death Records