New Results on Nucleon Structure in the Valence Quark Region at Large Bjorken-x

Lepton scattering has provided a powerful tool in both establishing Quantum Chromodynamics as the correct theory for the strong interaction and for unraveling the internal structure of nucleons and nuclei in terms of the fundamental quarks and gluons (partons) constituents.  Structure functions extracted from inclusive scattering cross sections and their spin asymmetries provide critical information on this structure and depend on both the 4-momentum transfer and the Bjorken scaling variable, x, representing the longitudinal momentum fraction of the nucleon carried by the struck quark.  At large values of x, where the scattering is dominated by a single valence quark, the momentum distributions can be more directly related to the nonperturbative structure of the nucleon.  In this talk I will discuss recent developments in understanding nucleon structure at large x, from both polarized and unpolarized scattering, with particular emphasis on the new generation of experiments at Jefferson Lab utilizing the upgraded 12 GeV electron accelerator.