Everything I have learned or will learn about early photography and photographers in Maryland is based on the invaluable work of Ross J. Kelbaugh.
He has been collecting Maryland photographs and researching Maryland photographers for decades. If you want to know anything about early Baltimore and Maryland photographers, if you want to know anything about Maryland photography in the Civil War, or about photography and the Civil War in general, he’s your guy.
I have three of his excellent books so far:
The Civil War in Maryland: An Exhibit of Rare Photographs documents the exhibition Kelbaugh curated at the Maryland Historical Society in 2006.
An Introduction to Civil War Photography is a brief, clearly written, profusely illustrated soft-cover that does exactly what it says. I’ve read it three times already.
Directory of Maryland Photographers 1839-1900 is the bible for Maryland vintage photo collectors. Kelbaugh painstakingly gathered and collated information about Maryland photographers and studios using a variety of sources. This hard-cover labor of love, which includes reproductions of rare photos from Kelbaugh’s own collection and biographies of some of the most important photographers, is an essential reference work. I read it cover-to-cover as if it were a novel. I refer to it at least once a day.
You can buy Ross Kelbaugh’s books directly from him at his website, HistoricGraphics.com.