Dating to ancient Greek and Roman times, a basilica originally referred to a type of public building in which official business was conducted. Beginning in the 4th century of the Christian era, basilicas began to be used as places of worship. It was during this time that the constructionof the great basilicas of Rome was begun. Soon these basilica churches began to play a unique role in the life of the Popes and the universal Church.
Today, the term basilica refers to a special designation given by the Holy Father to certain churches because of their antiquity, dignity, historical importance, or significance as a center of worship and devotion. The National Shrine was named a Basilica on October 12, 1990 by Pope John Paul II.
The Basilica of the National Shrine is the largest Catholic church in the Western Hemisphere and the eighth largest in the world. It measures a total of 459 feet long and covers an area of 77,500 square feet. The Knights' Tower, a gift of the Knights of Columbus and competed in 1959, rises 329 feet from ground level. The interior of the Great Upper Church is 399 feet long and can accommodate more than six thousand worshipers. The Crypt Chruch is 200 feet long, 160 feet wide and can comfortably seat more than 400 persons.