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.
Exterior 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. Architectural historian
Henry-Russell Hitchcock believed that the
onion-shaped domes atop the two towers were “not of Latrobe's design,” but now it is believed that they "were entirely the architect's own."
Interior 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 shortly after the 1821 opening of the Basilica.
Dome Latrobe originally planned a masonry dome with a lantern on top, but his friend
Thomas Jefferson suggested a wooden double-shell dome (of a type pioneered by French master builder
Philibert Delorme) with 24 half-visible skylights. For the inner dome Latrobe created a solid, classically detailed masonry hemisphere. Grids of plaster rosettes adorn its
coffered ceiling.
21st-century restoration A 32-month, $34 million restoration project was completed in 2006. The restoration included a total incorporation of modern mechanical systems throughout the building, while also restoring the interior to Latrobe's original design. Many "misguided accretions" were corrected. The original wall colors (pale yellow, blue, and rose) were restored, as was the light-colored marble flooring which for decades had been a dark green color. Twenty-four skylights in the main dome were re-opened, and the stained glass windows (installed in the 1940s) were given to St. Louis parish in
Clarksville (whose new church was designed around them) and replaced with clear glass windows. Additionally, the Basilica's crypt was made accessible to the public, as well as the expansive masonry
undercroft (basement) of the church. The undercroft, until 2006, had been filled with sand from the original building of the cathedral, which prevented Carroll and Latrobe's vision of a Chapel in the undercroft. During the restoration, the sand was removed, and the
Our Lady Seat of Wisdom Chapel was finally realized.
Cardinal William Keeler, then Archbishop of Baltimore, and one of the many champions of the restoration project, completed the restoration without dipping into the coffers of the Archdiocese, instead using private funds donated for the sole purpose of the restoration. The Basilica was closed to the public from November 2004 through November 2006, reopening in time for the Basilica's Bicentennial and the biannual meeting of the
United States Conference of Catholic Bishops, which was held in Baltimore to mark the occasion. The historic pipe organ was originally built by Thomas Hall (1821), and later rebuilt by Hilborne L. Roosevelt, (1884), Lewis & Hitchcock (1931), Schantz Organ Company, (1989) and Andover Organ Company (2006). The organ was played in recital during the Organ Historical Society Convention in July 2024.
2011 earthquake On August 23, 2011, an
earthquake that jolted the East Coast from Georgia to Quebec rattled through the Basilica, sending nearly 1,000 linear feet of cracks through its ceilings and walls. A seven-month, $3 million restoration was completed on Easter Sunday 2012. ==Notable interments==