Albert Naegeli was a well-known New York City portrait photographer who operated a studio in Union Square from 1876 to his passing in 1901. A fine working account of his gallery was published in 1884:

Naegeli, Photographer and Artist,  No. 46 East Fourteenth Street, Union Square. —Perhaps in modern science no more extensive improvements have been made in the last few years than in that of photography. The dry process of taking the negative has entirely revolutionized the art, it being far preferable and superior to the old method. The business of Mr. Naegeli was established in 1864, and since its removal to its present location in 1876 has grown to be one of great importance, the artist rapidly winning name and fame in consequence of the softness and modulation of his portraits. His gallery is a very fine one, admirably arranged and equipped with all the best instruments and materials known to the art, and he is capable of taking any size or style of picture. Portraits are executed in oil, water-colors, pastel, crayon, and india-ink, in the highest style of art, from locket to life size, from original pictures or from life, at very moderate prices, satisfaction being guaranteed in all cases. Much depends upon posing the subject in an easy and natural position, and it takes much time and patience and a considerable amount of artistic talent to master this very essential branch of the business. Mr. Naegeli having had great experience is a perfect master of this as of all other branches of his profession. He is a native of New York, and has made hosts of friends in consequence of his strict honor and integrity, and indeed there is nothing wanting in this first-class establishment, his work being excellent and his prices extremely reasonable. (1.)

Naegeli, as listed in the March, 1879 issue (vol. XXVII) of Wilson’s New York City Copartnership Directory, (p. 42) is joined in the Union Square studio with photographer and author Edward M. Estabrooke . (b. 1837)  Seven years earlier, Estabrooke had written the popular tintype manual: The Ferrotype, And How To Make It and subsequently authored the volume Photography in the Studio and in the Field in 1887.

Naegeli died at 57 after he shot himself accidentally:

Albert Naegeli, one of New York City’s best known photographers, died in the Post-Graduate Hospital, New York, on January 16th, from the effects of a pistol shot accidentally fired by himself. Mr. Naegeli was fifty-seven years of age and was held in high esteem by all who knew him. His studio on 14th street, where he had been for twenty-five years, will be remembered by many. Mr. Naegeli leaves a large family and a wide circle of personal friends. (2.)

The gentleman depicted in this portrait reads The World newspaper.

titled within lower plate impression:

A Study by Naegeli.
   Union Sq. New York.

1. New York’s Great Industries: Historical Publishing Company: New York and Chicago: 1884: p. 216
2. Naegeli obituary: in: Anthony’s Photographic Bulletin: E. & H.T. Anthony & Co., publishers: New York: February, 1901: p. 63