"In 1892, the Deutsche Evangelische Synode von Nord-Amerika (German Evangelical Synod of North America) voted to set aside its former seminary property as a home for epileptics to be called the Emmaus Asyl für Epileptiker und Idioten (Emmaus Asylum for Epileptics and Idiots) for persons with mental retardation and epilepsy. Pastor Carl Schnake became the first superintendent of the home when it opened on July 4, 1893. The first resident arrived on July 5th, coming from New Orleans. Emmaus was the first institution of its kind west of the Mississippi.
In the 1900 book by William Pryor Letchworth entitled Care and Treatment of Epileptics, the author describes the Emmaus Asylum near Marthasville, Missouri:
The charity was organized by Rev. C. Schnake. Two buildings of stone, spacious, well lighted, and well ventilated, afford accommodations for fifty patients, and, together with the residence of the Superintendent and a small chapel, comprise the buildings of the colony. The estate contains 240 acres, the greater part of which has not been cleared and fitted for field use.
The Emmaus Asylum for Epileptics and Idiots was also known as the Emmaus Asylum for Epileptics and Feeble-Minded, and later was called the Emmaus Home for Epileptics and the Mentally Retarded. Today, Emmaus Homes is a ministry of the United Church of Christ and continues to serve developmentally disabled people in a number of locations in the St. Charles, Missouri area."
According to the topographic map, the dirt parking lot at the bottom part of the property is where the main building/asylum/sanitarium was located.