Statistics for occurrence #1 of “John Duff” in chapter 9, page 94 of Thomas Wentworth Higginson, Harvard Memorial Biographies:

... him by blood and marriage. It was recovered on the night of the second day by the steadiness and good conduct of five men of his regiment,— Sergeant Le Roy Williams, Privates Galen S. Hicks, John Duff , Walter Harwood, and Samuel Travis. When Mr. Cozzens, in reading his memorial of Colonel Porter to the Century Club in New York City, narrated this fine act of affection,—how on a rainy night...
Max. Freq. Min. Freq.
Entity Corpus Doc Corpus Doc  
John Duff 17 4 1 0 0 user votes
John Duffy 16 0 0 0 0 user votes
John Duffer 2 0 0 0 0 user votes
John Duffes 2 0 0 0 0 user votes

† This entity has been selected by the automated classifier as the most likely match in this context. It may or may not be the correct match.