A high strength, ultra-fine grain (UFG) aluminum alloy plate of appreciable size (~62 cm diameter x 1.9 cm thick) has been produced using cryomilled powders, consolidated by quasi-isostatic (QI) forging and rolling. To recover strength losses attributable to grain growth during thermo-mechanical processing (TMP), sections of the plate were cold-rolled to reductions of 20, 30, 40 and 50 %. Trends in dislocation densities and grain sizes were quantified by transmission electron microscopy (TEM) to explain the mechanisms responsible for strengthening the UFG plate. After annealing, the cold-rolled material, some strength loss was witnessed, but surprising improvements in tensile ductility were also seen. To better understand the mechanisms, electron backscatter diffraction (EBSD) was used to carefully characterize the strain-hardened microstructure before and after annealing. The EBSD analysis shows the effect of cold work and subsequent annealing on grain boundary angles, grain size, texture and accumulated strain in the plate.