Over the last several years, physicists interested in understanding the structure of matter at the fundamental partonic (quark and lepton) level have come to realize that an electron-ion collider can address many of the outstanding questions in hadronic physics. In Summer 2000, a new Long Range Planning Exercise was announced for nuclear physics in the United States, and the proponents of an electron-ion collider came together to make the scientific case for this machine. This workshop summarizes the physics case and machine design for a next generation facility to study the fundamental structure of hadrons. Topics include: Spin and flavor structure of the nucleon, semi-exclusive processes, heavy quarks/target fragmentation, e-A physics, and machine.