St. Joseph the Worker Parish was established by the Most Reverend Henry P. Rohlman on November 1, 1949 in order to serve the west side of Dubuque which was rapidly expanding after World War II. The Rt. Rev. Msgr. Michael J. Martin, former president of Loras College, was appointed the first pastor. Parishioners came from Cathedral, Nativity, St. Anthony and St. Columbkille to form the new parish of St. Joseph. The first Mass at St. Joseph Church was celebrated on Christmas Day, 1950.
Construction of the first building, a combination church/school building on St. Joseph Street, began in 1950. The Dominican Sisters of Sinsinawa, Wisconsin were engaged to teach in the school and, in the fall of 1950, 165 children were enrolled. As the parish grew an addition was made to the school, the rectory was renovated and a convent was built.