In 1832 and 1833 a number of German Catholics settled in Sherman Township. At first it was called St. Germain and shortly after Sherman Settlement. It was closely associated with the Catholic Settlement at Thompson. The faithful settlers from Sherman went to Thompson to worship, which was a distance of four miles. As the Thompson parish grew, it became necessary to establish a Mission at Sherman. This was done in 1846.
The first church was constructed of rough hewn logs. It was opened for worship on July 2, 1846. Services in the beginning were held monthly and eventually, every Sunday.
The Sanguinist Fathers from the Thompson Mission Center looked after the spiritual welfare of the Mission.
A pastoral residence was built in 1867. The mission had grown considerably and needed a priest to reside in the parish grounds. The first resident pastor was Father John Thoma, C.P.P.S. He came in July 1868.
The original log chapel was replaced in 1857 by the present brick church.
A frame school was built in 1862 about two miles from the church. The second school was built on parish grounds west of the church in 1868. This building was of brick construction.
In December 1869 we came under care of secular priests. In 1894 the church was renovated on the interior and exterior. In 1897 a new pipe organ was installed.
The original school was closed around 1900, and a new three classroom school was built. The old school on the parish property continued to be used until it was damaged by fire in 1967 and was then razed. The Sisters of Divine Providence from Covington, Kentucky taught until 1946. At this time the Sisters of St. Francis from Tiffin took over teaching the children.
In 1922 the sanctuary and sacristies were enlarged. The old Gothic steeple was removed and replaced with the Romanesque style steeple. The vestibule was also enlarged.
In December 1940, fire did damage in excess of $13,000. The church was renovated and restored following the fire.
The school ceased to be parochial in 1948 when it became a part of Seneca-Huron School District. The public school district used the school buildings at St. Sebastian until 1967. The Sisters of St. Francis continued to teach at Bismark until students were transferred to a new school.