Series I consists of three slightly different copies of a book manuscript with mounted photographs, postcards, correspondence and commentary by Edward A. Jennings about the buildings and career of Arthur B. Jennings. The three copies are nearly identical, but a few differences exist; volume two holds more original correspondence than the other volumes, and building coverage differs slightly in each of the volumes as noted in the box listing. The book was never published. A list of buildings depicted is available in the box listing under the first copy; only the differences from copy one have been noted under copies two and three. Three folders of duplicate prints from the volumes are available at the end of the series.

Photographs are arranged in book manuscripts in their original order. They are listed here alphabetically by state, city and building name. The volume in box 1 includes a page index at the end of the volume. Dates indicate date of each building's erection, not the date the photograph was taken.

Series II. Church Architecture consists of an album compiled by Edward A. Jennings, comprised of postcard views of churches and chapels across the United States. A few of the postcard views in this album are of churches designed by his father, Arthur B. Jennings, but the vast majority simply reflect his wide-ranging interest in the design and structure of churches across the United States.

Postcards remain in original order in the album; they are listed here alphabetically by state and city for the researcher's convenience.

Series III. Manhattan Architecture and History consists primarily of unpublished book manuscripts with mounted photographs and clippings compiled and written by Dr. Edward A. Jennings on the history and architecture of Manhattanville, but also includes photographs and other materials relating to the Manhattan neighborhoods of Morningside Heights, Washington Heights, and the Upper West Side of Manhattan. The Manhattanville volumes were written by Dr. Jennings around 1940, incorporating research he did at the New York City Department of Records and his collection of historical photographs of the area straddling Manhattan Street (which was renamed West 125th Street in 1920). Included are descriptions of the history and landscape of the area along with depictions of local residences, including the Jennings family home, and such neighborhood institutions as Manhattan College, St. Joseph's Roman Catholic Church, the D.F. Tiemann & Co. Color Works, the Dolly Varden Railroad Manhattanville Station, Knickerbocker Hospital, and St. Mary's Church. Copy photographs of lithographs, drawings, and maps are included in the volumes.

The remaining materials in this series depict buildings in Morningside Heights, including Columbia University, in Washington Heights near Dr. Jennings' home at the time of his death at 2 Pinehurst Avenue, and a few buildings on the Upper West Side. Also included are notes for a slide lecture on the history of Harsenville and Bloomingdale, the current Upper West Side of Manhattan.

Materials are arranged by Manhattan neighborhood and thereunder alphabetically by subject.

Series IV. consists one scrapbook including a few clippings, maps, and photographs relating to Short Hills and nearby Summit, New Jersey where the Jennings family lived on Highland Avenue between 1881 and 1886 in a house of Arthur B. Jennings' design. Jennings also designed many of the houses in this planned suburban area, including a few belonging to family members in Summit. Several photographs of the Jennings home with the family gathered on the porch are present, along with a simple street map and an obituary concerning the death of the suburb's founder and planner, Stewart Hartshorn. Two original A. B. Jennings sketches of Short Hills houses he designed are included with the folder of Short Hills residences. Loose photographs from the collection depicting architecture in Short Hills and Summit are included in folders following the scrapbook.

Series V. Jennings Family consists of photographs and albums documenting the family and professional life of Dr. Edward Jennings, including his siblings, parents, and extended family. Formal photographs portray a variety of Jennings and Allen family members. Albums relate to Dr. Jennings' medical career, education, and extracurricular activities at Wesleyan and Columbia Universities. Photographs of Dr. Jennings with ambulances and staff from Fordham and Harlem Hospitals are included. One album pertains to Arthur Bates Jennings, Jr.' s career as an organist; it contains photographs, sheet music of works composed by Jennings, church bulletins and programs for performances. A family album holds informal snapshots of members of the Jennings family in a variety of settings. Oversize photographs at the end are primarily group portraits from hospitals and schools with which Dr. Edward Jennings was associated.

Photographs are arranged in three subseries: photographs, negatives, and albums. Thereunder they are filed alphabetically by sitter or group. Oversize group portraits are filed at the end of the series.