The bulk of this collection consists of glass plate negatives. The photographs document both everyday life and special events, such as parades, in the Bronx and throughout New York state, from the end of the nineteenth century to the beginning decades of the twentieth century. Standard New York scenes of the time period are depicted, such as the Brooklyn Bridge, Central Park, Coney Island, and Riverside Park, but most views are in the Bronx.

Stonebridge's fascination with military matters shows in the breadth, and the number, of military subjects he shot. Photos show troops staging sham battles and engaging in practice maneuvers at camps. Special military events, many in connection with the Spanish American War, are also well represented. Stonebridge photographed the memorial arch erected in Madison Square in Manhattan to honor Commodore George Dewey, as well as the Land and Naval Parades held in 1899 to celebrate Dewey's victories in the Philippines. Stonebridge also photographed the funeral of Civil War General Franz Sigel, held on 24 August 1902, and the military ships docked in the Brooklyn Navy Yard.

Stonebridge was interested in documenting disasters, such as train wrecks and fires. He managed to capture some of the sense of chaos and trauma that resulted from the fire on board the wooden excursion boat General Slocum on June 15, 1904. Over 1,000 people, mainly women and children, were burned to death or drowned. Stonebridge's photos show bodies being recovered from the water, families identifying bodies and clothing, and much of the rescue effort.

Many of Stonebridge's subjects were familiar Bronx views or projects. The building of the Bronx Zoological Garden and of the New York Botanical Garden are well documented. Pictures of the zoo construction show construction workers, inspectors, and the animals on display. Events or landscapes in Van Cortlandt, Crotona, Jerome, and Claremont parks are documented. Some of these parks were used for both military and civilian purposes. The construction of bridges over the Harlem River is shown in several series. Washington Bridge and High Bridge are well represented. Photographs of houses and streets in the Bronx neighborhoods of Fordham and Tremont show daily life and architectural details of the area. Stonebridge's employer, the Northern Gaslight Company, is also represented.

Like perhaps any photographer, Stonebridge took many photos of his family, especially when his three children were young. In addition, the family spent time in Garrison, New York, perhaps with extended family or at a vacation house in the country. Photos show the children engaged in play with farm animals and goofing around for the camera. In February 1905. Stonebridge built a snow house in his yard, and the children are shown playing on top of and inside the structure. Two contemporary newspaper reports about the snow house are filed with the mounted photographs.

Excursions and trips to the beach, both small and large scale, are shown in many of the series of photographs in this collection. The largest group pertains to Orchard Beach at City Island, where Stonebridge's family and many others stayed in tents, sailed, played games, and relaxed. The photographs from this locale date from 1907-1916, as the family returned year after year, often for Labor Day festivities. The Stonebridge family is also pictured at the beach in Ocean City, New Jersey. Larger, multiple family excursions to other Bronx beaches, such as Locust Grove, and Port Morris are shown. Stonebridge also photographed Niagara Falls, already quite a well-photographed tourist attraction.

Sport activities are also well represented. Stonebridge photographed bicyclists (he seems to have been an avid cycler himself), ice skaters, and children playing baseball. He also took pictures of races at a speedway, an airship exhibition, gardens and gardeners. Photographs also cover more mundane subjects such as portraits, street scenes, churches, club buildings, and houses.

In addition to photographic material, the collection includes a logbook of photographs kept by Stonebridge, and a number of his grammar school records and certificates of merit.