The Math Forum @ Drexel, http://mathforum.org, has an entire section on the history of mathematics, readily found by typing history in the search option.
As you arrive to start your journey through the history options, you will be presented with three major choices, as follows:
Math Forum: Famous Problems in the History of Mathematics
History of mathematics presented through famous problems, with some exercises and their solutions. Done in conjunction with the Math Forum, the home of Ask Dr. Math.
Math Forum: Discussion/Mailing List: math-history-list
An unmediated discussion group about the history of mathematics for announcements of meetings, new books and articles; discussion of the teaching of the history of math; and questions you would like answered. Subscribe to the mailing list or read and post from the Forum's Web archive.
Math Forum: Math Library - History/Biography
The Math Forum's Internet Math Library is a comprehensive catalog of Web sites and Web pages relating to the study of mathematics. This page contains sites relating to History and Biography
The famous problems section has a delightful selection of historical questions including the Bridges of Konigsburg, Zeno's Paradox, and an entire section on the question, "Are there more integers or more even integers?" Each section begins with a well written overview of the historical background of the problem to be discussed. The problems are clearly articulated and the solutions, or lack thereof, are explained well. With judicious choices, some sections might be used to enrich both middle school and high school mathematics' classrooms. The problems provide a valuable resource for use with preservice teachers and history of mathematics students.
The discussion group provides a forum for those interested in particular issues and/or questions in the history of mathematics. It is as though you are participating in those wonderful discussions at a conference that take place in the hallway or over a cup of coffee.
The search option in the math library provides links to a wealth of information. A particular historical topic can readily be accessed without being overwhelmed with an absurd number of sites. This section is a valuable tool for teachers and students of mathematical history.
A sincere thank you to the creators of this outstanding site!
Gail Kaplan, Associate Professor of Mathematics, Towson University