This series includes materials documenting Webb's architectural career and the various projects on which he worked, including blueprints, floor plans, stained glass window designs, and other technical drawings; photographs and engravings; correspondence; agreements; news clippings; brochures; programs; and advertisements. The majority of the blueprints, floor plans, and other technical drawings and designs are contained in the oversize boxes.

Among Webb's projects represented in the series are Carnegie Library (Northport, Long Island), Cypress Hills Abbey (Brooklyn, N.Y.), Fairview Mausoleum (Fairview, N.J.), Ferncliff Mausoleum (Hartsdale, N.Y.), Holy Cross Cloister (Brooklyn, N.Y.), Hotel Fort Montagu (Nassau, Bahamas), Memorial Abbey (Queens, N.Y.), Mount Lebanon Cemetery (Brooklyn, N.Y.), Public School No. 6 (West New York, N.J.), Williams Mausoleum (Brookville, Long Island), and various private homes and apartment buildings, among many others.

Additional items include two volumes of professional publications containing architectural plans and designs by Webb's colleagues; a certificate to practice architecture issued to Webb by the Commonwealth of Pennsylvania; a loose oversize volume of architectural compositions by Henry P. Kirby (d. 1915) and ephemera relating to Webb's projects; and a scrapbook of additional correspondence, architectural drawings, photographs and engravings, and clippings and ephemera relating to Webb's work and architecture in general.

This series contains materials relating to Gregory B. Webb's wife, Clarine Matson Webb, including correspondence, brochures, newsletters, clippings, and additional ephemera. These items illuminate Clarine's involvement in local social and cultural affairs, with an emphasis on her activities as an alumni representative of the Class of 1900 of Adelphi Academy in Brooklyn, and her involvement in several historical societies and museums, particularly the Long Island Historical Society (later the Brooklyn Historical Society). A photographic portrait of Clarine is also included.

The series also includes a diary belonging to Isabel Hawxhurst Hall, an artist specializing in book illustrations, ornamental rugs, and stained glass window designs. While the nature of Hall's relationship to the Webbs is not fully known, the entries and supplemental items contained throughout her diary suggest that she was a personal friend of Clarine's and may have worked with Gregory in a professional capacity. In addition to daily entries, Hall's diary contains stained glass window drawings and designs, correspondence, newspaper clippings, photographs, and programs relating to fine and performing arts, literature, fashion, architecture and interior design, social and cultural life in New York City, and the events of World War II. There are also several postcards that seem to have been collected by Hall while on various vacation trips.

This series is comprised of original and photocopied political cartoons collected by Gregory B. Webb, as well as miscellaneous materials such as articles, satiric pieces, and a set of sheet music. Most items have been clipped from newspapers and pasted onto cardboard, often bearing period advertisements on the verso. The subject of Theodore Roosevelt dominates the series, and more often than not his persona, policies, and initiatives (particularly the Spanish-American War) are treated in a sharply satirical or critical light. A smaller amount of cartoons pertain to President Franklin Delano Roosevelt and are similarly critical of his New Deal politics. Most of the clippings are culled from newspapers published in New York City, especially the Brooklyn Daily Eagle. However, the series includes many clippings taken from newspapers across the United States, including the Washington Post, the Nashville Daily News, the Philadelphia Inquirer, the Salt Lake Herald, the Boston Post, and the Portland Oregonian.