In 1922 Bishop Heelan surprised many by announcing a new parish would be built for families living north of 21st Street between Myrtle and Chambers. Blessed Sacrament Parish was named by Bishop Heelan from his great devotion to the Blessed Sacrament. The school opened its doors in 1924 with five classrooms and the parish church in the basement. The Dominican Sisters of Sinsinawa, Wisconsin were in charge of instruction. Msgr. Newman Flanagan (pastor from 1933-73) was instrumental in building the church and the 1962 addition to the school which included a gym, kitchen, and additional classrooms.

Father A. J. Huewe supervised the construction of St. Michael's School during 1952-1953. The school opened their doors August 31, 1953, with a total of 139 students in grades first through eighth. In the spring of 1954, the 8th grade class, with 14 students became the first graduating class of St. Michael's School. A second story was built on the school during 1961-1962. In September of 1981 the first kindergarten class was started at St. Michael School. An addition to the first floor was begun in 1984 and completed in September of 1985. This made space for a multipurpose room for the parish, music room, a larger kindergarten, and bathroom facilities. In 1995 a computer lab was added. In 1997 the library was refurbished and the school became networked for Internet and intranet access. With the influx of new students a new kindergarten room took over the music room in the fall of 2001.

In 2003 St. Michael merged with Blessed Sacrament to become Holy Cross School. Students in grades K-2 attend St. Michael Center and students in grades 3-8 attend Blessed Sacrament Center.