Reports of Spanish brutality in Cuba led many Missourians to support a war with Spain in 1898. The sinking of the battleship Maine in Havana Harbor on February 15, 1898, only strengthened the support, as cries of "Remember the Maine!" echoed across the country and jingoistic politicians and yellow journalists urged a free Cuba.

On April 25, the United States Congress declared war on Spain. Missouri was asked to provide five regiments of infantry and one battery of light artillery. Inadequate appropriations made it difficult to camp, feed, clothe, and equip the men. Governor Lon Stephens' determination to be fiscally responsible left the soldiers with leaky tents, insufficient bedding, and worn-out uniforms before the official call to mobilize. However, because the war lasted less than four months, none of these state troops saw action. Battery A of light artillery was sent to Puerto Rico as part of the First Army Corps, but arrived as the armistice was being announced. The Sixth Volunteer Regiment, organized after President William McKinley's second call for troops, arrived in Havana in December to assist with the occupation of Cuba, and served there for three months.

Over 8000 Missourians served in the state's National Guard; none were killed in enemy action, although there were many deaths from accidents and disease. Approximately 3500 Missourians volunteered in the regular armed forces; over half enlisted in the Army.

Individual Missourians in the regular Army and Navy saw action, though, in Cuba and the Philippines at San Juan Hill and Manila Bay, respectively. Several companies of an African American regiment, known as the "Seventh Regiment of Immunes," were raised in Missouri and sent to Georgia for training before being mustered out in February 1899. Some Missouri women who volunteered for nursing service were sent to Santiago. Over $500,000 worth of Missouri mules and horses were purchased for Army use.

Source: Soldiers Database: War of 1812 - World War I