author
Known for a lively 19th-century political biography, this writer is associated with Pine to Potomac, a book about James G. Blaine that also includes a sketch of General John A. Logan. Very little biographical information appears to survive online, which gives the work an old-fashioned air of mystery.
E. K. Cressey is credited as the author of Pine to Potomac: Life of James G. Blaine: his boyhood, youth, manhood, and public services; with a sketch of the life of Gen. John A. Logan. The book was published in 1884 and focuses on the life and public career of the American politician James G. Blaine.
Reliable online sources I found point clearly to that book, but they offer almost no confirmed personal details about Cressey beyond the name on the title page. Project Gutenberg lists only this work under the author, so it is safest to describe Cressey as a little-documented writer remembered mainly for this period biography.
For readers, that makes Cressey an interesting figure: an author whose surviving reputation rests on a single historical work from the late nineteenth century, written in the energetic, character-driven style common to biographies of that era.