The Basilica of the National Shrine of the Immaculate Conception is a large minor Catholic basilica and national shrine in the United States in Washington, D.C., located at 400 Michigan Avenue Northeast, adjacent to Catholic University. The shrine is the largest Catholic church building in North America, and one of the largest in the world; the basilica is also the tallest habitable building in Washington, D.C. Its construction of Byzantine Revival and Romanesque Revival architecture began on September 23, 1920, with renowned contractor John McShain and was completed on December 8, 2017, with the dedication and solemn blessing of the Trinity Dome mosaic. The basilica is the national and patronal Catholic church of the United States, honoring the Immaculate Conception as Patroness, accorded by Pope Pius IX on February 7, 1847. Pope Pius XI donated a mosaic rendition of the image in 1923. The shrine has merited several papal visits: Pope John Paul II raised the National Shrine to the status of Minor Basilica on October 12, 1990. Pope Benedict XVI bestowed a Golden Rose on April 16, 2008. Pope Francis canonized Saint Junípero Serra, O.F.M., on September 23, 2015. Although the basilica is situated within the geographical boundaries of the Archdiocese of Washington, the basilica is not a parish of the archdiocese, does not have its own parish community, and the shrine’s administration does not fall under the direct authority of the Archbishop, but it serves adjacent Catholic University, which donated the land for its construction, and the United States Conference of Catholic Bishops. It also hosts numerous Masses for various organizations of the Church from across the United States. The basilica is not the cathedral of the archdiocese, as that title and honor belongs to the Cathedral of St. Matthew the Apostle, although numerous archdiocesan events are held at the basilica. As of 2022, the rector of the basilica is the Reverend Monsignor Walter R. Rossi, who holds a Licentiate of Canon Law.