As Ian Wardropper, director of the Frick Collection in Manhattan, remarked at the preview for the new exhibition Turner’s Modern and Ancient Ports: Passages through Time, J.M.W. Turner created his 1820s seascapes at a moment of shifting borders. Travel restrictions due to a fear of invasion had meant that the English Channel could not be crossed between 1797 and 1815, but with the defeat of Napoleon at Waterloo, the barriers were lifted. “In celebration of this freedom of travel, he started making these sketches and traveling around the continent,” Wardropper said.

While it’s always a pleasure to take a long look at a Turner painting (if you’re a fan of 19th-century luminosity, that is), any exhibition is necessarily viewed from its current moment. The opening and closing of international borders and the impact of those decisions on art are especially relevant right now, in the wake of Trump’s travel ban in the US and Brexit in the UK. Turner’s monumental port painting of Cologne features a dog and disused fishing net whose solitude is about to be disrupted by a docking boat of well-coiffed tourists. And even as he exhibited this sunset-lit arrival in 1826, many of the old buildings and walls it depicted were being demolished to make way for development.

Along with the era’s modernization and freedom of exchange, Turner’s Modern and Ancient Ports considers the artist’s obsession with light in his mid career, facilitated by new synthetic pigments like chrome yellow and orange. The exhibition is organized by Susan Grace Galassi, senior curator at the Frick; Turner scholar Ian Warrell; and Joanna Sheers Seidenstein, curatorial fellow at the Frick; and draws largely on two collections, the Frick’s and the Tate’s. Central to the show is a trio of large-scale paintings, each representing a different port, a repeating theme for Turner that symbolized beginnings and endings and the shifting of time. In the middle of the trio hangs a murky blur of pigment that seems like one of his later works, like his whaling scenes, in which he broke down nature into chaotic shapes. In fact the painting is unfinished.

The incomplete work was among the bequested items from Turner’s studio that are now at the Tate. Its display with the other two finished paintings, acquired over a century ago by Henry Clay Frick, marks the first time the three have met. The grouping offers a rare view of a stage of his 1820s work, revealing how Turner built up the broiling color on a white-primed canvas, which was radical for a period when most contemporaries were using earthen tones. Appropriately, one of the three “ancient” ports representing classical scenes on the opposite wall responds to the story of Regulus, the Roman general whose eyelids were cut off by the Carthaginians so that he went blind by staring at the sun. You might feel slightly sunstroked if you try to find him on the canvas, where he’s suggested by a few fiery brush strokes amid the brightness.

The three “contemporary” ports of the 1820s were painted at a time of mass industrialization, when European seasides were bustling with new steamships and manufacturing hubs. However, Turner’s people and sleepy sail-powered ships seem to come from a pre-steam past. “He represented them at a point just before disappearing,” said Galassi at the preview.

A tiny sketchbook he took to Dieppe, France, shows Turner’s impressions of port life that would be blown up into the huge 1825–26 “Harbor of Dieppe,” which hangs alongside. It shows in ethereal tones a pre-industrial coast and a light that never existed. As critics of his era pointed out, the warm hues in the work were more of a Southern port characteristic. The Frick’s press release includes several choice quotes from scandalized viewers of the salons, who were not used to monumental canvases portraying everyday life rather than history. “Harbor of Dieppe” was “a specimen … of mingled truth and falsehood,” one stated.

In the accompanying catalogue released by Yale University Press, Ian Warrell describes Turner’s seascapes as “poetic topography.” In the second gallery, over 30 watercolors and prints on loan from the Tate, MFA Boston, Baltimore Museum of Art, Harvard Art Museums, Seattle Art Museum, and other institutions further illustrate this romantic perspective, often painted so that the viewer feels as though they’re a voyager riding a vessel into port. Warrell writes in his essay:

These watercolor scenes (professionally engraved to reach a wide audience) might appear to be simply skillful, picturesque representations of notable places across Britain, ornamented with the quotidian details of nineteenth-century life. Invariably, however, they are richly allusive, steeped in historical references or observations on contentious current issues, and thereby demonstrate Turner’s desire to create scenes that act as portals through which the viewer can contemplate much that is not actually depicted.

And they’re not completely devoid of rising industry. While the hovering orb of the sun, reflected in the water, offers much of the light in the exhibition, an 1823 watercolor titled “Shields, on the River Tyne” is a notable exception. In it, the moon glows in a night sky swirling with cool texture. Below is an orange ember, burning from a furnace into which workers are heaving coal for the shoreside manufacturing centers. Although some of Turner’s port paintings recall a nostalgic past, the present is always haunting the view, with the sun-soaked settings acting as a gateway between lost history and a rapidly dawning future.

Turner’s Modern and Ancient Ports: Passages through Time will be on view from February 23 to May 14 at the Frick Collection (1 E 70th Street, Upper East Side, Manhattan).