Moses Coit Tyler was born in Griswold, Conn., Aug. 2, 1835 and graduated at Yale in 1857. He was professor of English at Michigan University in 1867-81 and from the latter year to his death, Dec. 28, 1900, held the chair of American History at Cornell. In this address, Prof. Tyler has added to his equipment as a philosophical historian his personal knowledge and experience of the service that a properly administered collection of books may render to a community. Looking over the entire course of American society, from its rough and hardy beginning, in the first years of the 17th century, I find six distinct stages of development with reference to the possession and use of books by the people. The first stage is that of private libraries; the second is that of special institutional libraries, like those of colleges and other learned corporations, and intended for a limited and rather scholastic class in the community; the third is that of association or joint stock libraries, _i.e._, libraries of a more miscellaneous and general character, but for the use only of those whose names are on the subscription list; the fourth is that of common school libraries; the fifth is that of endowed libraries, _i.e._, public libraries founded and sustained entirely by private endowment and thrown open to the public without any cost whatever to the public; and finally, the sixth is that of free public libraries created, it may be, by private benefaction, but sustained in part at least at the public cost, _i.e._, uniting the two elements of private help and public selfhelp, and cherished by the public only as people will cherish that which costs them something, and of which they have some sense of real ownership.