Visitors stay cool as they float on the lazy river at the Audubon Zoo's Cool Zoo Water Park in New Orleans, Monday, May 27, 2019. According to the Audubon Zoo, more than 1,800 people visited the Cool Zoo on Memorial Day. The park is officially open 7-days a week through the summer.

As summer was about to begin this year, author Tony Horwitz dropped dead in Washington, D.C. while on a promotional tour for his new book.

Horwitz’s untimely death on May 27 understandably overshadowed what would be his last work, “Spying on the South.” But as summer closes and the shock of Horwitz’s passing subsides, perhaps more readers will discover his literary swan song and benefit from what it has to say. That would be an especially good thing in Louisiana, which figures a lot in Horwitz’s narrative.

“Spying on the South” is about Horwitz’s travels below the Mason-Dixon line as he retraced some of the earlier journeys of the 19th century landscape architect Frederick Law Olmsted, who’s best known as the mastermind of New York City’s Central Park.

Before Olmsted began designing public spaces, he worked as a journalist for the fledgling New York Times, going into what would soon become the Confederacy to explain the region to readers up north. Olmsted was charmed by some of what he saw, but he didn’t care for the rigid social hierarchy that put plantation owners at the top of the heap. His travels sharpened his desire to advance a more egalitarian America, inspiring him to create parks that could be enjoyed by everyone.

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In recreating some of Olmsted’s odyssey, Horwitz spent a good deal of time in Louisiana, and his accounts of life here are among the best parts of “Spying on the South.” When a torrential rainstorm hampers his travels, Horwitz and his traveling companion “holed up for seventy-two hours in Lafayette, staying with friends of a long-ago newspaper colleague of mine. Our hosts passed the indoor time force-feeding us etouffee and jambalaya.”

Horwitz listens to old newsreels at a museum in Baton Rouge, finding the rhetoric of martyred Gov. Huey Long freshly relevant. “As I listened to Long fulminate against the ‘favored few’ and champion the little man,” he tells readers, “Bernie Sanders was voicing similar themes on the campaign trail. Trump tapped this populism, too, with a style and tactics that Huey foreshadowed.”

In New Orleans, Horwitz considers Olmsted’s legacy in Audubon Park, which was masterminded by Olmsted’s design firm after he retired. “As for Olmsted’s dream of bringing people together,” Horwitz writes of his visit to the park, “the great majority of those I passed (or who ran or cycled or grunted past me) had buds in their ears. It was a public park filled with individuals in private silos, sharing space but little else.”

It’s proof enough that more than a century after his death, Frederick Law Olmsted’s ideal of common ground remains a work in progress. We have Tony Horwitz to thank for that timely reminder.