Secrets of the US Capitol
The US Capitol is one of America’s most iconic landmarks, but beneath its grandeur lies a trove of mysterious secrets and untold stories. From secret tunnels to ghostly hauntings, the Capitol is steeped in history, symbolism, and intrigue. Here are five mysterious secrets of the US Capitol that will leave you fascinated and eager to learn more.
1. Secret Tunnels Beneath the Capitol
These secrets of the US Capitol begin with the labyrinth of tunnels that lie deep beneath the Capitol building. These tunnels connect the US Capitol to nearby government buildings, including the Library of Congress and Senate offices.
Originally built in the early 20th century, these tunnels were made to allow members of Congress quick and secure travel. Today, some of these tunnels include a small subway system as well. However, the Capitol’s first-ever tunnels date back to the late 1800s, but the underground system expanded significantly during the Cold War, adding bomb shelters and secure escape routes.

2. The Dome Isn't Marble
Secrets of the US Capitol are not always underground, sometimes they are in plain sight, like the dome of the building. While the Capitol dome appears to be made of marble, it is actually constructed from cast iron. Completed in 1866, the dome replaced the original wooden structure and weighs an astonishing 9 million pounds. The dome’s intricate details, such as its Corinthian columns and decorative reliefs, are painted to resemble marble. It’s a triumph of 19th-century engineering, blending art and functionality.
Architect Thomas U. Walter designed the dome during the Civil War as a statement of resilience, symbolizing that the Union would endure despite the conflict. The dome’s iron structure reinforces the idea of strength and unity, core principles of the American Covenant. It stands as a testament to enduring ideals, even under the strain of war.

3. Masonic Symbols in the Capitol
Our secrets of the US Capitol would be nowhere near complete without mentioning its tie to Freemasonry. The Capitol is filled with Masonic symbols, reflecting the influence of Freemasonry on early America. From the cornerstone ceremony in 1793, performed with Masonic rituals, to the stars, pentagrams, and fasces found throughout the building. All of these symbols are deeply embedded in the Capitol’s design. The Capitol’s floor plans and artwork incorporate geometric patterns often associated with Freemasonry, sparking speculation about secret messages embedded in its design.
Many Founding Fathers, including George Washington, were Freemasons, and their principles of liberty, equality, and morality shaped the nation’s foundations. These symbols emphasize the idea of a divinely guided nation built on order, enlightenment, and moral integrity.
4. George Washington's Crypt
Beneath the Capitol Rotunda lies a crypt originally intended to hold the remains of George Washington. The crypt was completed in 1827, with plans for Washington’s body to be displayed in a grand national tomb. Congress even passed a resolution requesting the relocation of his remains, but his family declined. Washington’s will specified that he be buried at Mount Vernon, leaving the crypt empty to this day. Though the crypt itself may not be a secret, it is not a very well-known fact, which is why it has a spot on our list of Secrets of the US Capitol.
The crypt now serves as a symbolic space, with 13 statues representing the original colonies encircling the room. Some see it as a metaphor for America’s unrealized potential or a link to its spiritual foundations. Washington’s life and legacy are often tied to the American Covenant, as he is seen as a leader who exemplified divine purpose and moral strength in founding the nation.



5. The Capitol's Demon Cat
Perhaps the most unlikely of the mysterious secrets of the US Capitol, is the legend of the Demon Cat. This ghostly feline is said to haunt the building. According to lore, the black cat appears as a normal-sized feline but grows to a monstrous size before vanishing. Said to lurk in the Capitol’s basement and crypt, this Demon Cat’s paw prints have allegedly been left in the cement after a restoration.
Reports of the Demon Cat date back to the 19th-century, with sightings before major national tragedies, such as Lincoln’s assassination and the Stock Market Crash of 1929. While the legend may be pure folklore, it adds to the Capitol’s aura of mystery. Some even interpret the cat as a dark warning tied to the spiritual vigilance required to maintain a covenant-based nation.
Learn More Secrets of the US Capitol
The US Capitol is more than just a building, it’s a symbol of the nation’s history, ideals, and mysteries. These secrets of the US Capitol contain fascinating elements that reflect the layers of America’s past. Exploring the mysterious secrets of the US Capitol offers a glimpse into the stories, symbols, and legend s that continue to shape and maintain the American Covenant.
See the US Capitol and other sites on our Sacred Histories: American Covenant Tour. Learn more deeply about the founding of our nation, Freemasonry, Knights Templar Influence, the Pilgrims, Book of Mormon peoples, and even the Restoration of the Gospel.