Dorothy Seymour Mills, who collaborated for more than 30 years on a landmark three-volume history of baseball with her first husband, Harold Seymour — although he refused to credit her — died on Nov. 17 in Tucson, Ariz. She was 91.
Her friend Charmaine Wellington said the cause was complications of an ulcer.
The Seymours’ work, which traced organized baseball from its roots until 1930 in the first two books, then detoured to a focus on amateur baseball in the third, has long been considered the first significant scholarly account of baseball’s past.
“No one may call himself a student of baseball history without having read these indispensable works,” John Thorn, Major League Baseball’s official historian, wrote in Baseball Research Journal in 2010.
Ms. Mills played numerous roles in the creation of “Baseball: The Early Years” (1960), “Baseball: The Golden Age” (1971) and “Baseball: The People’s Game” (1990). She was their primary researcher, scouring libraries and archives throughout the country; she organized the project, edited the books before they were submitted for publication, typed the manuscripts and prepared the indexes; and she wrote a large…