From nearly the beginning of the United States, Americans have used arches to make visual arguments about the nation’s ideals.When George Washington arrived in Philadelphia after his election as president in 1789, he was welcomed by an arch of laurels and evergreens. Among its erectors was the painter Charles Willson Peale, who also made a 46-foot arch of painted canvas and wood that briefly stood in front of the city’s President’s House, where Washington would live for the bulk of his two terms. Arches, a form that linked the new North American nation to the classical Europe that had informed the Founding Fathers’ republicanism, helped give the U.S. a legitimizing past.Ever since, artists have used arches to celebrate U.S. republicanism, including to alert us to the plutocratic and autocratic forces that might corrupt it. In other words, they have issued warnings against the very qualities that the latest proposed arch—which President Trump wants to build across the Potomac River from Washington, D.C.—would embody.Trump’s arch would fill a traffic circle between the west side of Memorial Bridge and Arlington National Cemetery, and form a sight line with the Lincoln Memorial. It would be white with gold details that include a winged figure, two birds, and the phrase ONE NATION UNDER GOD. At 250 feet tall, it would dwarf neighbors such as the U.S. Marine Corps War Memorial (78 feet), the White House (70 feet), and the Lincoln Memorial (99 feet). Renderings of the proposed arch, which the U.S. Commission of Fine Arts approved on Thursday, indicate that the structure would provide a framed view of Confederate General Robert E. Lee’s home, now a National Park Service–administered site. (The CFA is an independent federal agency that reviews architectural changes in D.C. All seven of its commissioners were appointed by Trump. The arch will go before another body, the National Capital Planning Commission, in June.) In October, Trump showed off a model of the arch, first to donors to his ballroom-expansion project and then to the media. When a reporter asked the president who it was for, he said, “Me.”Trump may be unaware of—or at least seems uninterested in—the historical relationship between arches and U.S. republicanism, a term that’s out of fashion today but that was at the core of the political system adopted by the nation’s founders.Republicanism included the right to choose our own leaders, and the expectation that the common good would be prioritized over individual glory, gain, or elevation. Perhaps the most radical element of republicanism was that the nation’s sovereignty would be held by its citizenry rather than by a monarch or an autocrat. All of this was a considered response to European systems within which a tiny plutocracy had built power and control over land and people, especially through familial inheritance. So Americans embraced Roman triumphal arches—symbols of that ancient republic—almost from the start.The ancient Romans built arches to mark battlefield successes and important public events. Among those that remain standing are the first-century C.E. Arch of Titus and the fourth-century C.E. Arch of Constantine, in Rome. Among those that are no more is the Arch of Nero, which the emperor Nero built around 62 C.E. to salute martial victories, and which was likely destroyed shortly after his death about six years later. Today it is known only through a coin from the period.Within the United States, the Arch of Nero was made prominent by the artist Thomas Cole. While traveling just outside of Tivoli in 1832, Cole sketched the ruin then popularly believed to be the Arch of Nero. Cole developed those sketches into the 1832 painting A View Near Tivoli (Morning), which he exhibited to acclaim in New York. (Unbeknownst to Cole, the arch he painted was not Nero’s but part of an ancient Roman aqueduct.) Cole returned to those sketches around the time that the U.S. instigated the Mexican-American War, in 1846. The war was particularly popular among white southerners who lusted for new territory. For many northerners, it was a brazen attempt to expand enslavement westward while boosting southern influence in Congress.[Read: Don’t just replace Chavez—rethink monuments]Cole’s 1846 The Arch of Nero should be understood as a response to a growing sectional crisis—not the war itself, not the enslaving system it would extend, but the very idea of the American nation. The Arch of Nero both honored republicanism and warned that it was being corrupted by the war and, inevitably, its aftermath.The painting shows a lush, verdant Italian landscape, whose richness allows even peasants to enjoy leisurely strolls along its paths. The right-hand side of the picture is dominated by an enormous red-brick arch in a moderate but evident state of decay. Plants grow in the arch’s walls and across its top. The viewer sees that these healthy plants will continue to grow, that their root systems will advance into the arch and corrupt it, and that the plants will eventually cause the arch to disintegrate—a gradual undermining after a period of failed vigilance. Cole included two details no doubt intended to ensure that we understand that The Arch of Nero is about his era’s United States. First, the sunlit inside wall of the arch features a white patch of cement or mortar that is marked with blue-and-red graffiti. Cole repeated his use of the U.S. national colors in the painting’s lower right, where we find a red-white-and-blue-attired goatherd.Photograph by Timothy Tiebout. Source: The Philadelphia Museum of Art / Collection of the Thomas H. and Diane DeMell Jacobsen Ph.D. Foundation.The Arch of Nero, Thomas Cole, 1846.Crucially for Cole’s metaphor, Nero’s rule was notorious for tyranny, self-dealing, and extravagant public spending on the construction of monuments to and for Nero himself. For example, Nero built himself a preposterously large, expensive palace, which included an enormous rotating dining room. It was known as Domus Aurea, the “Golden House.” That the arch was Nero’s is everything to the meaning of Cole’s painting: Rome’s republicanism gave way to autocracy and imperial vanity thanks in part to Nero. The future Nero helped bring on was the future Cole evidently wished the United States to avoid.After Cole’s Arch of Nero, American artists such as G. P. A. Healy and Sanford Gifford used arches to reference U.S. nationhood. In the early 1850s, Frederic Church painted The Natural Bridge, Virginia, a view of a famed rock feature on land that had belonged to Thomas Jefferson. Whereas Church’s teacher Cole had addressed the U.S. by way of Italy, Church heeded Ralph Waldo Emerson’s call to make culture about the idea of the United States by using the country’s nature metaphorically. Before Church, artists had most often emphasized the horizontality of Natural Bridge; they presented the “bridge” atop the land feature rather than the keyhole that formed the arch. Church refocused our attention by emphasizing the arch’s verticality; nature’s form, like our system of governance, was fragile. At the bottom of the painting, a Black man gestures to Natural Bridge while he converses with a white woman. As the Union was fracturing, Church indicated that republicanism and egalitarianism must coexist for the nation to endure.During the Gilded Age, American architects built on artists’ interest in arches. Stanford White updated Philadelphia’s evergreens-and-laurel arch as well as the Arch of Titus with his design of New York City’s 73.5-foot Washington Square Arch, a commemoration of the first president’s 1789 inauguration. Brooklyn’s Grand Army Plaza features John H. Duncan’s 80-foot Soldiers’ and Sailors’ Memorial Arch, a Civil War monument.Contemporary artists have also nodded to arches in their conjoined address of past and present. In 1991, Cady Noland made Metal Fence, an arch built from a chain-link barrier. The U.S. was then fighting in the Persian Gulf; 1991 is also when four Los Angeles police officers assaulted Rodney King. Against those backdrops, Noland’s work seemed to ask why the U.S. was fighting a war in support of a monarchy, and why a republic was committing violence against its own citizens. Thirty years later, the Cleveland Museum of Art exhibited Metal Fence anew. Noland requested that the sculpture, which she originally had presented as a freestanding structure that viewers might walk through, be installed leaning against a wall; after Trump’s baseless contestation of an election and his incitement of the January 6 insurrection, U.S. republicanism was so diminished that it had to be propped up.Buyenlarge / GettyFrederic Church’s Natural Bridge, Virginia, 1860.Not all U.S. arches reference republicanism. Some laud the nation’s rapaciousness. The arch most conceptually aligned with Trump’s monument to himself might be the Gateway Arch in St. Louis, completed in 1965. Designed by Eero Saarinen, it nominally extols westward expansion—which is another way of saying imperialism and the removal and killing of Native Americans. The largest arch in the nation, at 630 feet, the Gateway Arch uses magnitude—and an observation deck—to try to sell its ideology.[Read: The real fight for the Smithsonian]An artist recently used his own arch to critique America’s past and its present. In the just-concluded “Monuments” exhibition at the Museum of Contemporary Art, Los Angeles, Kahlil Robert Irving critiqued the Gateway Arch with his 2024–25 Viewfinder, a tiny, cast-bronze version of the Saarinen. Irving installed it next to a much larger, three-part cast-bronze 2024–25 sculpture that he titled New Nation (States) Battle of Manassas—2014, a landscape that presents a fictionalized fallout of the police killing of Michael Brown in Ferguson, Missouri. (MOCA exhibited two of the three parts.) Irving’s presentation indicated that the officially sanctioned violence embodied by the Gateway Arch continues.Trump’s arch was proposed last spring by the architecture critic Catesby Leigh, but even he now opposes its planned grandiosity, which Trump insisted on. As with the Gateway Arch, the size is the point—an immensity so overwhelming that we might not notice the perversion of a classical symbol long associated with representative government. Trump’s arch is also so outsize that it would destroy the balance between the features of the National Mall and Arlington National Cemetery, hallowed ground that deserves deliberation and respect. Balance is another republican principle that Trump’s arch rejects.One of the reasons that art is valuable is its power to speak beyond the moment of its making. Cole, Church, and Noland surely hoped their alarms would not only be received in real time but gain voice over decades and centuries. Arches were warnings against rot. This time, the arch is the rot.*Illustration sources: Andrew Harnik / Getty; Bettmann / Getty; Demetrius Freeman / The Washington Post / Getty; Mondadori Portfolio / Getty; Sepia Times / Universal Images Group / Getty.