“Poor art for poor people.”

In the 1930s, the painter Arshile Gorky wielded that phrase like a weapon, disparaging what he saw as propagandist figurative art, art that often depicted and ennobled the American worker. And Gorky was far from alone in his scorn, as painting raced toward the purities of Abstract Expressionism. In his essay “Abstract Art Refuses,” Ad Reinhardt listed the numerous noes of his work, which included “no vested interests”; “no art history in America of ashcan-regional-W.P.A.-Pepsi-Cola styles”; and, most certainly, “no involvements.”

But the arrows of history and taste bend in mysterious ways. And with Labor Day at hand, New York finds itself — partly by happenstance, partly by design — in the middle of what might be described, with apologies to Gorky, as a rich moment for art about the working class, whose embattled existence is once again an issue in a presidential campaign. Over the last several weeks, I took myself on a rambling blue-collar art tour of the city, with help from a few curators and historians, visiting labor-themed art I’ve known for years — like the Josep Maria Sert murals at 30 Rockefeller Plaza, where I send visiting family to stand beneath the crotch of the colossus, who seems to be working not in a loincloth but in Fruit of the Looms — and finding dozens of pieces I’d never seen before, some because they’ve been in museum storage for years, or just acquired from private collections.

I tried to leave the definition of labor art as elastic as the 40-hour workweek has become. At the Whitney Museum of American Art’s new home in the meatpacking district, for example, the list included John Chamberlain’s gorgeous “Velvet White” from 1962, not because the artist had any intention of evoking labor with his crushed-car-parts abstractions — he hated the auto industry associations — but because you can’t help thinking about how much work went into the making, and then the violently poetic unmaking, of an automobile when you look at his pieces.

While I ended up focusing mostly on painting and sculpture from the early part of the 20th century — the work Mr. Reinhardt was reacting so testily against, much of it made under the fruitful auspices of the Works Progress Administration — I also wandered back cheerfully through centuries and millenniums. I stood until my legs got stiff in front of the Mona Lisa of New York labor paintings: Pieter Bruegel the Elder’s “The Harvesters” (1565), at the Metropolitan Museum of Art, where it has been for almost a century now, its peasants scything, sleeping and slurping their porridge on what was supposed to be a July or August day among the Netherlandish sheaves. (The guy in the black bowler gnawing his bread, staring you down goggle-eyed through the picture plane, has always seemed like the comic forefather of Chaplin and Keaton, Vladimir and Estragon. William Carlos Williams, in his poem about the painting, focuses on the lug sleeping “under a tree/whose shade/carelessly” he does not share.)