At the height of his career Sargent was the most sought-after portraitist in the Anglo-American world, with a waiting list of the eminent and wealthy. His sitters were far different from Eakins’ middle-class professionals and intellectuals; they were the upper crust, in all their glory. And he gave them the full treatment. Sargent belonged in the great worldly tradition of British portraiture, enjoying the spectacle of beauty, fashion and luxury, and knowing how to extract from them the maximum , pictorial effect.
The central [act in Sargent’s art was his extraordinary skill with the brush. His brushwork was a virtuoso performance which, like that of a brilliant pianist, gives its own kind of enjoyment. On the other hand, his standard portraits were not notable for human warmth or powerful realization of character such as Eakins had. By comparison, Sargent’s art was deficient in substance and plasticity, concerned with what meets the eye rather than fundamental form and design. But as a portraitist in the grand style he was a worthy successor to Romney and Lawrence. And frequently we find a different Sargent, painting a man or woman who interested him, or delightful informal pictures of his friends; and we wish that this gifted man had been a less successful portraitist and more often purely a painter.
(Lloyd Goodrich. Three Centuries oj American Art)

His mature portrait style was oriented to society and fashion -fluent, elegant, and dramatic, expressed in elongated forms and bravura brushwork, replete with aristocratic reminiscences of English portraiture from Van Dyck to Lawrence. Frozen into a position of success and affluence, he avoided challenges and problems, and there was no further development of his style. His willingness to please led to a succession of exquisitely groomed manikins of fashion—glossy, empty symbols of social position turned out with a technical dispatch that is somewhat repellent, as in Mrs. Hugh Hammersley (1893), but he Was also capable of a penetrating character study such as Mrs. Asher Wertheimer (1904) or Henry G. Marquand (1897).
(Milton W. Brown. American Painting to 1900)

JOHN SINGER SARGENT
(1856-1925)
The unhealthy atmosphere of the late nineteenth century in which American art had to develop became apparent not only in the indifference and hostility of bourgeois society to its greatest artists, but also in the corrosive lure of easy success which tempted many a good artist and marred his work. This corrupting influence is exemplified by the fate of Frank Duveneck (1848— 1919), William Merritt Chase (1849—1916), and John Singer Sargent (1856—1925), to mention only a few.
Sargent, the chosen portraitist of America’s elite, squandered his phenomenal talent on brilliant, masterly portraits of representatives of fashionable circles in Europe and America. His portraits appealed to the “Gilded Age” because of their technical virtuosity and the absence of any indication of a sitter’s character, such as may be seen, for example, in Eakins’ work. Sargent’s brilliant technique and unproblematic and ingratiating subjects, which tell little about the elite whom he portrays and much about the elegance, made him a much-sought-after society painter both in Europe and America.
Flashy and superficial society portraits are most predominant in his output, but now and then he was able to produce a truthful and sincere work with a profound revelation of character, boldness of design and subtlety of lighting that reveal his potentialities of a fine realistic master. Robert L. Stevenson, Suzanne Poirson, Mrs. Charles Gilford Dyer are among Sargent’s best works. <...). Sargent was born in Florence to American parents, and his early years were spent in leisurely travel through Europe. He studied first in Rome and then at the Academia in Florence before entering the studio of Carolus-Duran in Paris at eighteen. No radical, Carolus-Duran was a solid painter, inspired by the same sources of visual realism that influenced Manet, and Sargent received a thorough technical grounding. Immensely talented, he learned quickly, but his earliest works were slick rather than original.
However, after a trip to Spain and Holland in 1379—80 and a serious study of Velasquez and Hals, his style gelled suddenly into precocious maturity. His Mrs. Charles Gifford Dyer (1880) is a moving psychological study as well as a brilliant bit of painting. The Pailleron Children (1881) is startling in its naturalism and its emotional tenseness. The environmental clutter is reminiscent of Carolus-Duran, but a new objective reality in the figures, possibly from his interest in Velasquez, is more closely related to the English portrait tradition. There is even a curious affinity in some of Sargent's later portraits with the American tradition of Copley and Stuart.
It is interesting that Sargent had visited the Centennial Exposition, where he could not have missed the American paintings, At any rate, within the mainstream of visual Realism, he continued the English, rather than the French, tradition of portraiture both in its painterly virtuosity and in its occasional courtly vapidity. Characteristic is the Daughters of Edward Darley Boil (1882), perhaps his closest brush with greatness. Daring in conception and composition, lucid in execution and in the handling of light and space, capturing the vibrancy of the children and the total ambience, it nevertheless fails to move one deeply, perhaps because > the recording eye chose chic over aesthetic probity, or because the scale was too large and there are too many empty areas. In contrast, perhaps his most famous portrait, Madame X (1884), is in the French vein of Caroius-Duran, classical in pose and solidly painted. This likeness of Mme. Pierre Gautreau, a society beauty, mingles a flair for style and social elegance in the sheer elan* of the figure with an unexpected and disturbing fidelity to physical reality. Mme. Gautreau and her family were ostensibly outraged by the shocking decollete when the portrait was exhibited at the Salon, but they may have been equally upset by the vanity and the hint of vulgarity that Sargent, I perhaps unconsciously, revealed. Annoyed by the resultant hubbub, he withdrew the portrait, left the French art scene, and shortly afterward settled permanently in London. He was before I long an internationally famous portraitist.