In the last 10 days, I've become obsessed with borders. I finally have a chance to tell you about it. Yesterday (when I'm writing this) was the first free day at the International Arts Journalism Institute in Visual Arts in Washington, D.C., which I've been doing since June 10.

So far our group of 24 writers (12 domestic, 12 international) has traveled across D.C. and to Philadelphia and Baltimore; tomorrow we go to New York. We've seen show after show, and heard speaker after speaker. But the most important moments have happened in our private conversations, and when we've written about what we've seen, then talked about the writings in small groups.

A young Egyptian woman writing about Duchamp's peep-show masterwork, which we saw at the Philadelphia Museum of Art—this was my second time seeing it and it remains, to paraphrase Jasper Johns, the weirdest thing in any museum anywhere—is fascinating, let me tell you. Amira hated it. Deeply. Angrily. Other writers have gone right for the jugular of their experiences here, expressing in eloquent writing (in their second or third or fourth languages) their double bind—they're both grateful to this institute, and yet they can't help but find themselves in the belly of the beast they've been grappling with for years: the American culture, American power, American wealth, Americanness.

One of the defining conditions of being American is the ability to forget borders entirely if we really want to, to pretend they don't exist in the world because we don't need to use them. The U.S. is huge; something like only 18 percent of Americans have passports. But this condition of geography has bred a state of mind, too, right? Enter Frederic Edwin Church's painting Niagara (pictured above), which we visited last week at the Corcoran Gallery of Art. The painting is roughly the size of the top of a coffin for a very big man: 3 1/2 feet by 7 1/2 feet. Its size is large, but not huge. But people love it because its view seems to go on forever in all directions.

There are no figures in the painting—except you, looking, positioned near the edge of the falls, already in the water already and about to go over the edge. The falls have no visible bottom, just mist, as if you could fall for all time. You could rise for all time, too, into the opening in the clouds above the mist. And water stretches to both far edges of the canvas.

This landscape has no limit. Audiences went crazy for it when it was painted in 1857. The reason why was immediately understood: "It is a view of Niagara Falls which will cause all others ever painted to be forgotten," a reviewer wrote in the New York newspaper The Courier and Enquirer when the painting was first shown. "We know of no American landscape which unites as this does the merits of composition and treatment… The picture has no foreground, to speak literally. It is water to the base line, and water everywhere."

Looking at the painting now, it's easy to say that it's a historical artifact, like many Hudson River School paintings, representing the bygone era of Manifest Destiny. But it might also be possible to see it as an American dream that still endures: the dream of a world of pure potential and endless possibility, a place that is vast, self-enclosed, and without state-imposed borders. In Church's fantasy, America and the world are one seamless place without end—or, more cynically, the United States is so big that the rest of the world does not even need to exist.

This International Arts Journalism Institute in Visual Arts is a fresh chance to take a look at how we formulate and present Americanness through American art. Has so much money been spent in a single effort on promoting American art since the CIA took up the cause of peddling the abstract expressionists in the Soviet Union in order to advertise American "freedom" of expression? The first day here, we toured Washington's monuments (we skipped Maya Lin's Vietnam Memorial—huh?!) and a private collection of American illustrations. We've talked about Winslow Homer, Thomas Eakins, Marcel Duchamp, Charlie Chaplin, Sun Ra, Walead Beshty, Shepard Fairey, and we're about to take a look at the feminist Sackler Center at the Brooklyn Museum of Art and see Negritude at Exit Art in New York.

It doesn't always feel like we're getting to the heart of things. For instance, we went to an Asian art museum (the Freer) and focused only on its small founding collection of American art, ignoring the rooms and rooms of Asian works. Why not talk about the intersection/disconnect of ideas in American and Asian art? The different ways museums display American and European art as opposed to art from non-Western countries? The question of ethnography versus aesthetics? These are conversations we're not yet having. We have another five days.

But it is to the institute's eternal credit that the countries these writers represent are not Western European. I wonder: Did the state department mandate this? These countries are distinctly "Other" countries—places largely unvisited and, it's probably fair to say, widely misunderstood by average Americans (I'm not leaving myself out here), whose differences from the United States are undeniable and not necessarily easy to reconcile. Bosnia, Colombia, Egypt, India, Indonesia, the Philippines, South Africa, and Venezuela—those are the countries represented, and every single one represents a border that cannot be denied, a sometimes uneasy border that defies the easy fantasy of the "global village." In short, we have a lot to talk about—and, as Americans, we are not practiced at it. (How many of us know how to say "cross-cultural" in a language other than English?)

It's said that art knows no borders, but that seems the opposite of true. If you look closely enough—and that is the key, and what we're trying to do in D.C.—art is busy mapping borders, offering the potential of travel without tourism. At this institute, we are 24 writers trying to understand how to hold borders without guarding them. It's an experiment in trying to find and then reach across the limits of what we've long believed to be a basically limitless Churchian landscape.