"Basilica of the National Shrine of the Assumption of the Blessed Virgin Mary"

The cathedral is a monumental neoclassical-style building designed in conformity to a Latin cross basilica plan — a departure on Latrobe's part from previous American church architecture, but in keeping with longstanding European traditions of cathedral design. The plan unites two distinct elements: a domed space and a longitudinal axis. 

The principal feature of the main façade is a classical Greek portico with Ionic columns arranged in double hexastyle pattern, immediately behind which rise a pair of cylindrical towers. The exterior walls are constructed of silver-gray gneiss quarried from the Ellicott City Granodiorite.

The interior is occupied by a massive dome at the crossing of the Latin cross plan, creating a centralizing effect which contrasts the exterior impression of a linear or oblong building. Surrounding the main dome is a sophisticated system of barrel vaults and shallow, saucer-like secondary domes. The light-filled interior designed by Latrobe was striking in contrast to the dark, cavernous recesses of traditional Gothic cathedrals.

The Basilica houses many precious works of art, including two heroic portraits: the first entitled Descent from the Cross by Pierre-Narcisse Guérin and the second, by Baron Charles de Steuben, depicts Louis IX of France burying his plague-stricken troops before the siege of Tunis at the beginning of the Eighth Crusade in 1270. Both portraits were gifts of King Louis XVIII of France shortly after the 1821 opening of the Basilica.