American chemist and writer Harrie Irving Hancock is best known for his works on juvenile literature and children's books from the late 19th and early 20th centuries, as well as for creating a fictional account of a German invasion of the United States. On January 16, 1868, Hancock was born in Massachusetts. Laura (Oakes) Hancock and William Henry Hancock were his parents. Nellie Stein and Hancock were wed on December 21, 1887. Their two daughters, Doris Hancock and Vivian Morris Hancock, were reportedly adopted. Hancock was a prolific writer for Leslie's Weekly, the New York Journal, and the New York World who preferred to work at night. A significant portion of his work was produced in the genre of "boy's books" popularized by the renowned Stratemeyer Syndicate. This genre was created on the presumption-which proved to be extremely successful-that "boys want the thrill of feeling 'grown-up'" and that they enjoy books that provide them with that feeling, particularly those that are part of series in which the same heroes frequent each other.