Part of the pleasure of the "American Treasures" exhibit now at the Boca Raton Museum of Art derives from the intriguing juxtapositions of the pictures.

Albert Bierstadt’s The Oregon Trail, from 1869, heroic in theme as well as execution, is close by Jackson Pollock’s Silver and Black from 1950. Senior Curator Wendy Blazier believes that both paintings share a spirit of innovation.

I would say that’s true of the artists, but the paintings themselves are quite different. One is pure narrative, the other blunt color and texture. They’re both emotional, but the resemblance ends there.

Quibbles aside, this selection of 36 paintings from Youngstown, Ohio’s Butler Institute of American Art provides invariably first-rate paintings from a slew of first-rate painters. The industrialist Joseph Butler Jr. who left most of his estate to the museum he founded, had a good eye, a quality that has been maintained by the curators in the 80-odd years since Butler’s death.

The show even showcases first-rate paintings from second-rate painters – the Impressionist Childe Hassam could be erratic, but Manhattan Misty Sunset from 1911 is a beautiful rendering of the nascent New York skyline at dusk.

The exhibit basically tells the story of nearly 200 years of American painting through artistic bullet points – from Thomas Cole, who founded the Hudson River School in the early 19th century, to Pollock and his successors.

Cole’s Italian Landscape from 1839 pictures the artist sketching in the lower left of a large-scaled picture of a fantasy Italy, all wild foliage with some picturesque ruins for accent. Cole didn’t do well by the human figure, but his landscapes have some of the same epic grandeur that Bierstadt brought to the American West.

Moving into more modern times, Georgia O’Keeffe’s Cottonwood (1944) shows her making a tentative return to the pictorialist principles of her husband and mentor Alfred Stieglitz. The New Mexico landscape is soft, delicate and quite Impressionistic.

Other landscapes are less of a surprise. Andrew Wyeth’s Cow Birds, from 1988, is typically precise and evocative, while Edward Hopper’s charcoal House in Charleston from 1929 proves once again that whenever Hopper does a house he seems to be illustrating a Hawthorne story about generational doom.

Milton Avery’s The Baby, from 1944, is typically bright, evocative and witty, as Avery uses a couple of pink blobs in a chair to make a baby. Likewise, Andy Warhol’s 1979 Paul Jenkins is a strong portrait of the artist that uses Jenkins’ style of abstract brushwork for background. (It’s unclear who applied the background; since it wasn’t Jenkins, it was probably one of Warhol’s drones.)

For me, the prize of the collection was totally unexpected: Sylvia, by the unheralded (to me, anyway) William McGregor Paxton, who was clearly under the sway of Vermeer. It’s a portrait of a young lady done in 1908, and the opulence of the gilded age is certainly foregrounded.

The Paxton is next to Thomas Eakins’ The Coral Necklace, from 1904, an introspective, moody portrait of a young woman who’s studiously ignoring the necklace that Eakins used for his title.

The Paxton is mostly about the surface, the Eakins is mostly about what lies beneath the surface. But Paxton’s command of his technique, the beauty of his subject and the ambiguous expression in her face gives the portrait a touch of the infinite that every great portrait seeks, and few find.