Andersen developed a passion for books as a child and collected them all his life. As a young traveling salesman he saved his loose change and spent it on books. His hunt for books brought him into contact with dealers, other collectors, printers and librarians. He was well acquainted with book and auction catalogues; paging through them became a welcome break in a busy day. Andersen bought books with a purpose, to build a library. He intended to read his books, know them well, catalog them, and care for them. American and English history and literature and inspirational poetry were of particular interest to him, but as his interests expanded so did his reading and his library. When he came to Minnesota he became interested in the state's history. When he learned more about fine printing and printers his eyes turned towards William Morris and the Kelmscott Press. And when he discovered something new, like the Whittington Press, he made sure that the University of Minnesota owned the printer's entire archive.