The photographer and cultural impresario Alfred Stieglitz (1864-1946) made an enormous contribution to the acceptance of modern culture in America. He operated the gallery that gave such artists as Cezanne, Matisse, and Picasso their first American exhibitions. The magazine Camera Work, which he edited, was the first to publish the experimental writing of Gertrude Stein.
Stieglitz was himself one of the great photographers of the 20th century. Like St. Paul and many another convert, however, he found his true way only after setting forth in what turned out to be the wrong direction. This impassioned advocate of modernism in all the arts began as an aesthetic conservative.
''Winter, Fifth Avenue,'' made in 1893, is one of the earliest photographs to use the modern city as a subject for art. It marked a turning point for Stieglitz, who had until then largely confined himself to picturesque rural scenes.
To the documentary photographer, concerned with making a visual record, no subject had been alien. Criminals, corpses, and even city streets passed before his camera. But the conventional wisdom of the late 19th century held that the fine arts ought to concern themselves with nice people and places and things, and Alfred Stieglitz wanted to be considered an artist.
The ruins of Rome or the canals of Venice offered suitable subjects for art. Not only did the modern city lack the patina of age, it was tainted by association with commerce, industry, and political unrest. The considerations that had once led the French court to move from Paris to Versailles encouraged painters to look at the smiling countryside and ignore the turbulent city.
Alfred Stieglitz was born in Hoboken, N.J., and grew up in New York. When he was 19 years old his father took the family to live in Europe, in the best Henry James style. Although Alfred studied mechnical engineering at the Technische Hochschule in Berlin, he had a gentleman's view of art when he began making photographs in the 1880s.
While Stieglitz lived in Germany he photographed peasants, craftsmen, and village streets. It made no difference that industrialization was transforming Germany, or that he himself was an engineering student. To this ambitious young man, the artistic possibilities of photography were very nearly limited to those of the Currier & Ives greeting card and the coal-company calendar.
After he returned to New York, however, Stieglitz decided he could not go on making pictures inspired by villages in the Black Forest; he would have to find artistic value in the appearance of the modern city.
''Winter, Fifth Avenue'' was an early step in this new direction. In 1893 he still believed that urban buildings - even mansions on Fifth Avenue - needed to have their hard edges softened by such means as a blanket of snow, or dim light, or blurry focus. He had learned these devices from the Impressionist and Sym-bolist painters.
The decision to give up the hay wagon in favor of the city street was echoed by many 20th-century artists. During the years just before World War I the painters of the Ashcan School celebrated New York City. The Futurists, the Constructivists, and the Precisionists all made art out of urban and industrial forms.
Stieglitz pictured the changing appearance of New York City for decades. He was one of the earliest visual poets of the skyscraper, and he inspired such younger photographers as Berenice Abbott and Paul Strand.
''Winter, Fifth Avenue'' is a transitional work in the history of photography. It looks backward to the Christmas-card picturesque, and at the same time forward to art that embraces the reality of modern life.