The Mission was located about 35 miles (56 km) north of the Kansas-Indian Territory border.
When the Civil War erupted, Father John Schoenmakers wanted to keep the Mission as neutral ground and thus out of the conflict.
Although at one point Schoenmakers had to flee for a time, he pretty much succeeded in keeping Osage Mission itself out of harm's way.
At times from 1862 to 1865 Union troops were stationed at Osage Mission, almost certainly on its outskirts.
[2][3] In November 1863 Confederates entered the Mission and the small force there, under a sergeant, was powerless to effectively drive them off.