Church use In 1902, with the support of Father Joseph C. Mallon, pastor of St. Ann Catholic Church in Tenleytown, the Sisters of Providence of Saint Mary-of-the-Woods, an order of religious sisters based in Indiana, announced plans to open a religious school in northwest Washington on land purchased from St. Ann's rectory. Two years later, another plot of land, this one across the street, was bought to spare the rectory from demolition. The plans followed a request by Cardinal James Gibbons, Archbishop of Baltimore, for the establishment of a "select school for girls" in the District. A new building for this purpose was designed by architect Albert Olszewski Von Herbulis, and, on July 2, 1904, the cornerstone was placed atop what the Sisters dubbed "Mount Marian." The Seminary of Our Lady Immaculate – or "Immaculata," for short – was completed the following year. It was so named in honor of the golden jubilee of Pope Pius IX's Ineffabilis Deus, which defined the dogma of the Immaculate Conception of the Virgin Mary. On September 8, the school hosted Cardinal Gibbons, who blessed the structure and then helped conduct a solemn high mass at St. Ann's; a sermon written for the occasion was given by F. X. McCarthy of Washington's St. Aloysius Church. Additional guests at the ceremonies included Bishop of Indianapolis Silas Chatard, President David H. Buel of Georgetown University, and other representatives of Catholic churches and organizations from around the region. Mother Superior Mary Cleophas Foley, also present, received a congratulatory letter from Cardinal Sebastiano Martinelli in Rome, passing along well-wishes on behalf of Pope Pius X. In 1906, the Sisters purchased the rear portion of the block, consolidating the land that would later comprise the U.S. historic district. On December 8, 1955, the day of the Feast of the Immaculate Conception, Amleto Cicognani, Apostolic Delegate to the United States laid the cornerstones for three new buildings at Immaculata: Marian, Loretta, and Regina Halls. Acquisition by American University In 1978, following the closure of Immaculata Junior College, American University began renting space in Marian Hall to address the need for additional student housing; shortly thereafter, they also started leasing Immaculata's gymnasium for evening use. AU officially took possession on December 4, 1986. After renovations were completed, the campus housed the university's Washington Semester and study abroad programs. Purchased in 1987 by AU, Tenley Campus was acquired to alleviate space problems