The World Treaty Index was first published by ABC-Clio in 1974, ten years after its founder, Dr. Peter Rohn, envisioned a comprehensive resource for treaty research. Under the auspices of the Graduate School of the University of Washington and with initial funding from the National Science Foundation, Dr. Rohn created a resource designed to contribute to an empirical theory of international law and politics. The electronic collection of treaty citations allowed for the presentation of data in a variety of ways, permitting both qualitative and quantitative investigations.

The second edition of The World Treaty Index was published in 1984 and included a number of enhancements to the database. By this time, the resource contained over 44,000 treaty citations dating between 1900 and 1980. League of Nations treaties and treaties registered in the United Nations Treaty Series comprised about 50% of the total, while national treaty sources accounted for the remaining 22,000 documents. A full description of the database can be found in the introduction to the second edition.

Between 1984 and 1999, 25,000 additional treaty citations were added to the database, but a third edition of the Index has not yet been published. (The second edition of The World Treaty Index was reprinted in 1994 by William S. Hein & Co., Inc.). Dr. Rohn retired in 1989 and responsibility for the indexing project was assumed by Dr. Edmond Mignon of the University of Washington Graduate School of Library and Information Science. Dr. Mignon retired in the summer of 1999. Both he and Dr. Rohn continue to served as consultants on the project.

From 1999-2009, the World Treaty Index was administered under the auspices of the Human Rights Education and Research Network by Glenda Pearson of the University of Washington Libraries. During her tenure, Ms. Pearson oversaw the development of the Electronic World Treaty Index Search Interface.

Starting in 2010, the World Treaty Index entered a new phase with a dedicated URL (http://worldtreatyindex.com/) and complete site redesign. The site is now maintained by Michael Bommarito, Daniel Martin Katz and Paul Poast.. By the end of 2010, the Electronic World Treaty Index should feature complete coverage for all known agreements in the 20th Century. Furthermore, we anticipate the addition of a variety of extended search features.

For additional information on the history of the World Treaty Index, please see by Glenda Pearson, Rohn's World Treaty Index: Its Past and Future, 29 International Journal of Legal Information 543 (2001).