The history of St. Bernard begins in 1802 when seven Catholic families, originally from Maryland , migrated from Washington County , Kentucky to the Casey Creek region. These early Catholics first celebrated Mass in their homes and a traveling priest named Father Badin came by to serve their needs. In 1807, Trappist Monks built a monastery on the banks of Casey Creek but soon left in 1808. In 1810, Father Nerinckx helped those original settlers purchase over 400 acres of land (now known as the Chapel F
arm) and erect a small log church which he christened Saint Bernard of Clairvaux. The cost was over $800 and the now thirteen Catholic families shared the expenses. Two schools were erected on the Chapel Farm in the 1820's. Lorettine nuns established a convent and school for girls named Mt. Olivet and the Brothers of the Missions priests built a home for their order and a school for boys. Both schools closed prior to 1830. In 1860, Father Hutchins (a boyhood friend of Abraham Lincoln) erected a second church 4 miles from the first and christened it St. John Chrysostom. It too was small and made of log.

The Casey Creek settlements now had two churches but in 1881 the first church was torn down and St. John Chrysostom was re-christened St. Bernard of Clairvaux. That was also the year that St. Bernard held its first picnic to raise money to purchase a bell for the church. By 1890 the little log church couldn't hold the growing Catholic population so Father Gabe helped the families construct a new third church which was dedicated in 1892.
St. Bernard became a parish in 1897 when Father John Imhof became its first resident priest and a rectory was built for him (a rectory that still stands today). Unfortunately, Father Imhof died in 1900 and, at his request, he was buried at St. Bernard. In 1907, with over 640 parishioners, Father O'Shea helped construct a school at a cost of $3500. The first teachers were lay persons. However, three Ursuline sisters arrived in 1911 to teach and a house was soon built for them. The Ursulines taught at St. Bernard from 1911 to 1971. In January 1949, disaster struck when the beautiful church caught fire and burned down. Father Blandford headed the construction of a fourth church and a larger school at a cost of over $100,000. When the new church was completed, the first Mass was held on Palm Sunday, April 2, 1950. The students transferred from the little school to the new one on April 18, 1950. Due to low enrollment, the St. Bernard high school was closed in 1965 and the elementary school was shut down in 1971. A mission church of St. Bernard , Sacred Heart Catholic Church, was constructed in Liberty in 1987.