John George Nicolay

John George Nicolay (February 26, 1832 – September 26, 1901) was a German-born American author and diplomat who served as private secretary to U.S. President Abraham Lincoln and later, with John Hay, co-authored ''Abraham Lincoln: A History'', a ten-volume biography of the 16th president. He was a member of the German branch of the Nicolay family.

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