Symposium held in Baltimore, Maryland, January 2003. The Symposium was jointly sponsored by the SIAM Activity Group on Discrete Mathematics and by SIGACT, the ACM Special Interest Group on Algorithms and Computation Theory. Contains approximately 112 papers that were selected from a field of over 408 submissions based on their originality, technical contribution, and relevance. Papers cover such topics as discrete mathematics and graph theory, including combinatorics, combinatorial optimization, and networks. Although the papers were not formally refereed, every attempt was made to verify the main claims. Abbreviated versions of these papers may appear later in more elaborate form in various scientific journals.