Unsteady flow conditions present significant challenges to stable flight, and gust rejection remains a concern for flight control in many modern flight environments. Examples of gust dominated flight conditions include flight in stormy conditions, aircraft takeoff and landing in strong crosswinds or ship air wakes, and micro air vehicles in strong shear flow engendered by urban settings and complex terrain. Improving flight stability during gust encounters relies on an improved understanding of the flow physics and the development of effective mitigation control strategies. To this end, the present work seeks to (1) improve our understanding of the unsteady flow physics of a pitching wing encountering a transverse gust and (2) develop and characterize successful open-and closed-loop control strategies to mitigate aerodynamic lift transients induced by the gust using wing pitching input. Classic unsteady aerodynamic theory was used to construct the open-loop pitch maneuvers and tune the closed-loop controller for closed-loop control. The dynamical systems treatment of the problem during control design revealed several important physical features important to vehicle control.