On December 8, 1854, the Dogma of the Blessed Mother was defined by Pope Pius IX. The following year, on August 16, 1855, the first Immaculate Conception Church of Washington, PA was dedicated.

Prior to 1795, Catholics of West Alexander, Claysville and Washington were attended to by visiting priests of St. James Parish. In 1852, Rev. Daniel Hickey, who resided in West Alexander, PA, was appointed its first resident pastor. Then, in 1852, the first Immaculate Conception Church was built in Washington, PA on the corner of Lincoln and East Wheeling streets.

In 1900 construction began on a parochial grade and high school at the corners of North Franklin and West Chestnut Streets. The school opened in September of 1901. It was considered one of the most modern and best-equipped school buildings in the diocese and served the parish and surrounding area for the next fifty-five years. The Sisters of Mercy of Pittsburgh, PA, who lived in a convent built next to the school, staffed the school.

One of the problems facing Rev. Martin J. Hughes, who became pastor in December of 1911, was the lack of centralization of the church, rectory, school and convent. In 1915, he purchased additional property on West Chestnut Street next to the school. Plans for a new church were made, and construction began in 1929. The new Immaculate Conception Church was blessed and dedicated on September 1, 1930. Rev. Hughes was instrumental in building the church, and remained pastor for 42 years, from 1911 to 1953 until his death in June, 1956.

The church is of Gothic design. The walls are of masonry, with exterior faced with limestone. The altars are of Italian marble. The original plans were for a mural or mosaic on the wall behind the main altar. Due to the depression of the 1930s, plus the large debt placed on the parish for construction of the church, this was not completed. The stained glass windows were added in 1958-1959. Rev. Ralph L. Hayes, pastor of this time, chose the basic theme, “The Immaculate Conception in Scripture, Tradition and History,” for the windows. The church is believed to be the first church in this country to bear the name “Immaculate Conception of the Blessed Virgin Mary,” after the promulgation of the doctrine of the Immaculate Conception by Pope Pius IX on December 8, 1854.

Sacred Heart Church, a brick building, was built in 1874 the nearby town of Claysville, PA. This church remains in use today, serving the parishioners who live in nearby Claysville.