What exactly was “the wall”? On August 4, 2014, a second-tier New York City real estate developer turned television game show host took to Twitter to voice the demand, as he put it then, to “SECURE THE BORDER! BUILD A WALL!” This was the first time that the future president would declare his support for the endeavor and by no means the last time he would do so without furnishing any real specifics as to what precisely he had in mind. In fact, throughout his tenure, he never really explained what “the wall” was.

In November, the National Building Museum (NBM) in Washington, D.C., unveiled an exhibition that attempts to fill in the gaps. Curated by Sarah A. Leavitt, The Wall/El Muro is a modestly scaled but engaging, informative exploration of the odd history and troubled present of the United States’ southern border. More specifically, the show is about the structures—ranging from memorial-type markers to chicken wire, to tall fences, to somewhat taller fences—that successive presidential administrations have erected in an attempt to demarcate that border and render it less permeable. Through illuminating photographs, wall text, video, and artifacts, Leavitt, who previously served on NBM’s full-time curatorial staff, successfully walks a line as fine and as fraught as the conceptual abstraction that is the border itself. Two lines, really: On the one hand, how to render such a sprawling and complex subject in the space of a few white-walled rooms? On the other hand, how to do it in today’s polarized climate, without quickly alienating half the visitors?

The solution on offer at NBM is appropriately subtle. Especially through the use of real-life material collected at borderland sites, the show packs the small display space with the kinds of compelling, stare-worthy objects whose very aura speaks louder and more eloquently than any verbal polemic ever could: asylum application forms, an old section of chain link, the discarded belongings of migrants crossing the desert. The delicate yet creepy models of the 2017 wall “prototypes”—the ones that the previous presidential administration plonked down in the California desert, re-created here by Pratt Institute’s Ane Gonzalez Lara—as well as the gray gallery walls, perforated to resemble the barrier structures actually in place on the U.S.–Mexico border, all help produce an environment with exactly the right air of tension, confusion, and melancholy. About the only thing missing (though it does seem a glaring omission) is one of the old surplus Vietnam-era helicopter landing mats that were the default fencing material in the San Diego sector from the 1990s until quite recently. Their battered surfaces, and the singular histories they represented, would have made a perfect complement to the show’s layered ambience.

It would seem only fair at this point to disclose that I wrote a book on a related topic a couple of years ago, an architectural history of border walls generally and of the wall in particular—the “build the wall” wall, the one that was supposed to be made of solar panels or possibly of unscalably smooth supermetal, was supposed to run the whole length of the border and was definitely, definitely not going to be a “fence,” one GOP also-ran once suggested. In this connection, The Wall/El Muro was something of a trip down a very bumpy memory lane, full of familiar scenes and faces; even the livery of the wall placards was exactly the same red, white, and black as my book’s cover, though I’m quite confident this was pure coincidence. Written and researched at the same time that said presidential administration was trying (and trying, and trying) to remake the border, the book was really nothing more than a snapshot, a blurred image of something seen at too-close range and moving too fast. So what, with the perspective of at least a little time, does Leavitt now see?

The answer, worrisomely: still too much and still nothing good. The statistics, aerial photography, and documentary evidence on display in The Wall/El Muro suggest that the region and the topic remain as rife as ever with endemic problems, along with loads of misbegotten ideas—detaining children, for starters—to address them. If the NBM show is right, we can be all but certain that the border and its barriers will keep on providing political fodder for some of the worst tendencies in American political life. We’re no further out of the woods than we were a year ago, and we’re definitely not over the wall.

Ian Volner has contributed articles on architecture and urbanism to Harper’s, The New Yorker, The Wall Street Journal, and New York Magazine, among other publications. He is the author of numerous books and monographs, most recently Jorge Pardo: Public Projects and Commissions (Petzel, 2020).