Shortly after his arrival in New York for his 1882 Lecture Tour, Oscar Wilde posed for a series of photographs taken by Napoleon Sarony, then the most famous portrait photographer in America.
The main body of photographs were taken at Sarony's studio at 37 Union Square, New York City  on January 5th, 1882. They have become the most recognizable images of Oscar Wilde and the ones by which we most readily associate him today.
While Wilde was waiting for the photographs to be developed his touring manager, Colonel W. F. Morse, required an image of him for publicity purposes. He therefore commissioned the artist James Edward Kelly, a New Yorker of Irish descent, to make a sketch of Wilde for immediate use, and bas-relief from it for further prints.
Wilde revisited New York in August 1883 when Sarony took several more photographs, this time with Wilde's hair cut much shorter.
One of the photographs (number 18) became the subject of a copyright infringement suit by Sarony against the Burrow-Giles Lithographic Company, which had marketed unauthorized lithograph trade cards containing the image. The federal trial court for the Southern District of New York awarded a $610 judgment to Sarony (the equivalent today of over $13,000). The judgment was affirmed by the U.S. Circuit Court for the Southern District of New York, and subsequently by the Supreme Court of the United States.
Sepia vs Black & White
The Sarony photographs were originally developed in black & white but many will have undergone the yellowing process familiar in old photographs. This is the result over time of chemical changes in the albumen that was used during the period to hold the silver emulsion. The photographs are technically albumen silver prints from glass negatives.
For uploading to the Internet all images undergo a form of digital transfer. Those uploaded as a color image will retain this sepia tone. Other images however, appear black & white but this does not necessarily imply any more authenticity or originality, but is more likely the result of being manipulated to grayscale before uploading.
 Some sources incorrectly give Sarony's address as 87 Union Square. This stems from misreading the similar typography of the number 37 on Sarony's cabinet cards. For a comprehensive review of all Sarony locations visit ClassyArts.com - a web site of Andrew J Morris to whom I am indebted for his knowledge of historical photography.