Although calls to erect a national monument in Lincoln’s honor started almost immediately after his assassination, the project dragged on for decades. After the U.S. Congress in 1867 authorized construction of a monument on the U.S. Capitol grounds, sculptor Clark Mills designed a memorial tiered like a wedding cake that was cluttered with dozens of statues and topped by a bronzed depiction of Lincoln signing the Emancipation Proclamation. Fundraising, however, sputtered during Reconstruction, and the project fizzled. Not until 1911 did Congress approve $2 million to build a national memorial. After three years of contentious debate over its location and design and a lengthy construction process slowed by World War I, the Lincoln Memorial opened in 1922.

In selecting architect Henry Bacon’s design modeled after the Parthenon in Athens, the Lincoln Memorial Commission bypassed several eccentric designs proposed by architect John Russell Pope. In addition to his preferred design for an open-air, neoclassical monument, Pope submitted sketches of alternatives that included a stepped Mayan temple with a massive eternal flame on its summit, a ziggurat topped by a statue of Lincoln and an Egyptian pyramid with classical porticoes on each side. Although passed over for the Lincoln Memorial commission, Pope later submitted the winning design for the Jefferson Memorial.

At the monument’s groundbreaking on February 12, 1914, Lincoln Memorial Commission member Joseph Blackburn “turned the first spadeful of sod,” according to The New York Times. Prior to representing the martyred president’s native state of Kentucky in the U.S. Congress for nearly 30 years, Blackburn served as a lieutenant colonel in the Confederate Army during the Civil War. “This memorial will show that Lincoln is now regarded as the greatest of all Americans,” the former Confederate officer said at the simple groundbreaking ceremony, “and that he is so held by the South as well as the North.”

Although the memorial looks perfectly symmetrical, it’s an optical illusion. The structure’s exterior walls, facades and columns were purposely built to lean slightly inward, according to the National Park Service, “to compensate for perspective distortions which would otherwise make the memorial appear asymmetrical.”

Daniel Chester French, who sculpted the 19-foot-high statue of Lincoln for the memorial, invested considerable thought in how to position the president’s hands. “It has always seemed to me that the hands in portraiture were only secondary to the face in expression, and I depend quite as much upon them in showing character in force,” the sculptor wrote. French depicted Lincoln with his left hand clenched to symbolize his determination to see the Civil War through to its conclusion and his right hand open to represent a desire to welcome the vanquished Confederacy back into the Union without vengeance.

French tasked six brothers who had emigrated from Italy with chiseling Lincoln’s likeness out of 28 blocks of white Georgia marble. Already renowned for carving the New York Stock Exchange’s pediment and the Washington Square Arch in Greenwich Village, the Piccirilli brothers carved the slabs in their sprawling workshop in the New York City borough of the Bronx. When finished, the enormous blocks were transported to the memorial and delicately assembled like puzzle pieces with nearly invisible seams. Although French proposed engraving “Piccirilli Brothers” into the statue’s plinth, the humble carvers refused the honor.

Since the Lincoln Memorial is located on land reclaimed from the Potomac River’s tidal flats, 122 enormous concrete pillars and a foundation as deep as 65 feet in some spots were built to anchor the massive monument to bedrock. A three-story basement, known as the undercroft, sits below the memorial’s pink Tennessee marble floor. The cellar doesn’t contain any secrets, but stalactites hang from the ceiling of the cave-like area and cartoons scrawled by the memorial’s builders cover its pillars.

A worker who possibly grabbed the wrong stencil accidentally chiseled “EUTURE” instead of “FUTURE” when etching the words of Lincoln’s Second Inaugural Address into the memorial’s north wall. Although the bottom line of the “E” was filled in to correct the flub before the memorial’s dedication, remnants of the misspelling can still be spotted by a discerning eye.

While Confederate veterans were given seats of honor as a sign of national unity at the Lincoln Memorial’s dedication on Memorial Day in 1922, gun-toting soldiers ushered Black spectators far from the monument and behind a rope barrier to segregate them from white onlookers. “The conditions which confronted us as a race were most shameful,” wrote W.E.B. DuBois. Tuskegee Institute president Dr. Robert Russa Moton, the lone African American speaker at the dedication, was barred from sitting on the platform with his fellow orators, and the White House heavily censored his speech to remove comments about the need for further progress on racial justice such as this line about Lincoln: “This memorial which we erect in token of our veneration is but a hollow mockery, a symbol of hypocrisy, unless we together can make real in our national life, in every state and in every section, the things for which he died.”

To protect Washington, D.C., from a possible German aerial attack during World War II, the Army installed anti-aircraft guns at strategic locations around the national capital, including on the rooftops of buildings lining the National Mall. In September 1942, a crew accidentally fired four rounds from one of the guns. Three errant shots struck the Lincoln Memorial’s façade above the entrance. Luckily no visitors were injured, but one round left a lasting scar after gouging out a piece of marble the size of a baseball.