The ACLS History E-book Project by the American Council of Learned Societies began in 1999 with funding from the Mellon Foundation, with the goal of putting 500 important history books online for access through subscribing libraries. By 2008 it had published over 1700 titles online.
The books are selected by leading historians and are fully searchable; many titles link to online reviews in JSTOR. Users can undertake keyword and Boolean searches, search full text across all titles in the database, in selected titles, in a single title, or by select series, by author and title, as well as by Library of Congress subject headings. Users may also search important book reviews. Search engines allow readers to find text and graphics, and to perform complex string searches for names, dates, phrases, or concepts in great depth and context.
Over 400 libraries pay from $350 to $2000 annually, depending on an institution's size. The project has been self-sustaining since April of 2005. It is adding about 250 backlist titles, annually.