Nicolay, John George (1832-1901), a United States author and public official. He and John Hay wrote the authoritative Abraham Lincoln: A History (10 volumes, 1890), which was authorized by Lincoln in 1861. Nicolay was born in Bavaria. He came to the United States in 1838 with his family and attended Illinois public schools. He worked for the Pittsfield (Illinois) Free Press and was its owner-editor, 1854-56. Nicolay became a friend and supporter of Abraham Lincoln.

When Lincoln was elected President in 1860, Nicolay and his close friend, John Hay, were appointed his private secretaries. They served him throughout his Presidency. Nicolay was United States consul at Paris, 1865-69, and marshal of the U.S. Supreme Court, 1872-87.