"American art" is a catch-all category, encompassing early modernists like O'Keeffe and Ash Can school painters like Walt Kuhn and George Bellows as well as 19th-century American Impressionists such as Mary Cassatt and Hudson River School landscapists like Thomas Moran, plus masters of the art of the West like Charles Russell, and even American illustrators like N.C. Wyeth and Norman Rockwell. This spring, spectacular pieces were hard to come by, with no really great 19th-century works on the block -- a sign that the material is rare and in demand.

Christie's auction on May 23, conducted by the house's chief auctioneer, Christopher Burge, produced the week's most impressive results by far, selling 88 of 118 lots -- 75 percent -- for a total of $31,607,175 (all prices include auction-house premium). Sotheby's auction the following day, May 24, was rather lackluster, totaling $20,511,125 for a larger group of works -- 137 of 181 lots sold, about 76 percent by lot. Phillips Auctioneers, which conducted its sale at its 79th Street showroom rather than in its new ground-floor 57th Street space, came in a distant third, with a total of about $2.5 million for its May 22 sale of about 140 lots.

Christie's scored several records with its sale, led by the aforementioned O'Keeffe, Calla Lilies with Red Anemone (1928), which went to an anonymous buyer for $6,166,000. A large (ca. 48 x 30 in.) and flashy painting from the collection of the late Edith K. Ehrman, who acquired it from the artist in 1939 through Alfred Steiglitz's An American Place gallery in New York, it carried a presale estimate of $2.5 million-$3.5 million. The lot was accompanied by a letter from O'Keeffe to Ehrman discussing her efforts to frame the work in preparation for delivery. An O'Keeffe painting of a calla lily of this size last sold three years ago at Sotheby's in 1998 for about $2.6 million.

A second major O'Keeffe was the more dramatic and modernist Black Cross with Stars and Blue (1929). It sold for $4,076,000 to Owings-Dewey Fine Art in Santa Fe. The work, which was painted in New Mexico and first exhibited at An American Place, is one of a series of four large cross canvases from 1929.

The third highest price was brought by Maurice Prendergast's The Stony Beach (ca. 1897), the catalogue cover lot. An airy scene of turn-of-the-century American leisure, it sold for $3,526,000 (est. $2 million-$3 million), a world auction record for the artist. The work was owned by Arthur Altschul, former CEO of Goldman Sachs and a collector known for his holdings of works by artists of the Ash Can School and the Nabis Brotherhood.

A second, later Prendergast, an oil on canvas Bathers from the Ehrman collection that strongly suggested the influence of Cézanne's works on the same theme, failed to sell, however. It carried a presale estimate of $1million-$1.5 million.

Still another record was set when Edward Hopper's Charleston (1929) sold for $1,876,000 (est. $500,000-$700,000), the top price at auction for a work on paper by the artist. Hopper watercolors have sold privately for more, but in any case they are rare and much sought after.

Another interesting work in the Christie's sale was lot 100, John Marin's beautiful 1921 watercolor, Boat with Sun, Deer Isle, Maine (1921). It sold for $226,000, well above its presale estimate of $70,000-$90,000. Pictures of this quality don't come up very often, and this is the number two high price for Marin at auction (the Marin auction record of $610,750 was set last year for a work on canvas).

Other top prices in which the work sold for more than the high estimate included Mary Cassatt's portrait of Ellen Mary Cassatt with a Large Bow in Her Hair ($941,000); Martin Johnson Heade's Single Magnolia on Red Velvet ($831,000); Thomas Wilmer Dewing's The Music Lesson ($721,000); and Charles Russell's Rainy Morning ($644,000).

Sotheby's sale on May 24 featured a pair of Italian pictures by John Singer Sargent. The catalogue cover lot, Rosina-Capri (1878), which shows a 17-year-old local model dancing the tarentella on a rooftop, accompanied by a female musician with a tambourine, barely made it past its reserve to sell with premium for $5,395,750 (est. $5 million-$7 million). The price is the fourth highest at auction for a Sargent work; the record is about $11 million, set at Sotheby's in 1996. The second Italian picture, a Landscape study at San Vigilio, Lake of Garda (est. $300,000-$400,000), failed to sell.

Sotheby's second-highest selling lot was Walt Kuhn's powerful Roberto (1946), which sold for $1,105,750 (est. $300,000-$400,000). Easily one of the artist's best clown pictures, Roberto has a long exhibition history that stretches from its debut at Durand-Ruel in New York in 1946 to the Kuhn retrospective held in 1978 at the Amon Carter Museum in Fort Worth.

Another top lot at Sotheby's was Poppies and Italian Mignonette by Maria Oakley Dewing, which sold for $1,105,750 (est. $1 million-$1.5 million). Dewing is the wife of Thomas Wilmer Dewing and the painting is still in its original Stanford White frame; still, despite the accomplished decorative quality of this picture, she is hardly a major artist -- this is only the second work to come up at auction. But someone wants them; her 1901 painting of a rose garden sold a year ago at Sotheby's for a similar price -- about $1.1 million, though back then it carried a more modest estimate of $200,000-$300,000.

Other works at the Sotheby's sale that garnered good prices were Thomas Moran's Cascade Falls, Yosemite ($858,250), George Bellows' Cleaning his Lobster Boat ($555,750); Charles Burchfield's Backyards in Golden Sunlight; and Norman Rockwell's And Every Lad May Be Aladdin (Crackers in Bed) ($368,750).

(During the week, Sotheby's also held an auction of Old Master paintings on May 23, selling 93 of 147 works offered, or 63 percent, for a total of $7,508,750. Top lot was a Canaletto scene of Venice, which went for $1,050,750 (est. $1 million-$1.5 million).)

As for Phillips sale on May 22, top lot was a pencil and pastel of a White Breasted Hawk by John James Audubon, which sold for $255,500, well over the presale high estimate of $150,000. The two cover lots, Cassatt's 1898 pastel of Mrs. Harris Whittemore and Baby Helen (est. $2 million-$3 million) and Sargent's moody A Spanish Woman (Gigia) from ca. 1879-82 (est. $700,000-$900,000), were both bought in.