The death of Mrs. Lincoln was a serious loss to her husband and children. Abraham's sister Sarah was only eleven years old, and the tasks and cares of the little household were altogether too heavy for her years and experience.

Nicolay and Hay also edited Lincoln's Works in twelve volumes (1905). For some time after his return to the United States he edited the Chicago Republican. In the 1992 documentary Lincoln the German-born Nicolay is voiced by the Austrian-born actor Arnold Schwarzenegger.

He was Marshal of the United States Supreme Court (1872–87). The resulting biography is a definitive resource on Lincoln and his times. John George Nicolay (born February 26 1832 as Johann Georg in Essingen Rhenish Bavaria – September 26 1901) was an American (German-born) biographer secretary of US President Abraham Lincoln and member of the German branch of the Nicolay family.