Beginning in the 1850s, Williamston Catholics worshipped with visiting priests. They often traveled ten miles by carriage or horseback on rutted, muddy roads to St. Patrick Church in Woodhull (present-day Shaftsburg) to worship.

In 1866 two brothers, Jerome and James Waldo (who were also instrumental in building the National Block Hotel, q.v.), entered into a contract with Detroit Bishop Peter Paul Lefevre, stipulating that they would sell a plot of land in the village of Williamston to the diocese for twenty-five cents, provided that a church worth at least one thousand dollars was built within three years. During the winter of 1868 - 69, Owen Brannan and Peter Zimmer cut and hauled timber to construct the first of three Catholic churches on this site. And in 1869 a frame church costing eleven hundred dollars was completed on this site and named Saint Mary. Saint Mary Church became a parish in 1879, upon the arrival of the first resident pastor, Father John Lovett.

From 1889 to 1898, despite its growing membership, the parish did not have a full-time priest and it became a mission. In 1895 the original wooden church burned. A larger, brick, Neo-Gothic building was erected the same year. (see photo) Under the leadership of Father John J. Connolly, who served from 1898 to 1905, Saint Mary regained parish status. It comprised the church: a cemetery, founded in 1873: and a new rectory, erected in 1902. In the 1920s and 1930, community activist and priest, Father Francis McCormick was the pastor of this parish, and he has left a lasting impression on the community, not only for his pastoral work, but also because he organized and spearheaded the reclamation of the city dump on the riverfront adjacent to the church, and helped turn it into the park which bears his name today.

In 1948 a parish hall was built and in 1956 a convent was established for the sisters of Saint Joseph who staffed the school that opened in 1959, and continues as a K-6 school today (although the nuns are gone).

The present church was built, and the gorgeous Gothic church razed in 1985, however, the old bells were preserved, and remain on the site and in use today.

Descendants of St. Mary's founding families continue to worship here.