In this study, the microstructure and microscale deformation behavior of polycrystalline materials was characterized using an experimental approach combining several techniques. The evolution of full-field surface deformations was continuously tracked during in-situ mechanical loading, and the displacement and strain fields were obtained by scanning electron microscopy combined with distortion-corrected digital image correlation (SEM-DIC). Electron backscattered diffraction (EBSD) was used to characterize the undeformed microstructure, and combined with femtosecond laser ablation assisted serial sectioning to reconstruct the 3D microstructure from deformed samples. Localized deformation including slip and twinning were identified in the high-resolution strain maps, and subsequently correlated with the active deformation modes through quantitative analysis of the displacement and strain fields. The activity of slip and twinning, and their interaction at grain boundaries will be discussed. The experimental results will be compared with a crystal plasticity finite element model developed in an integrated computational materials engineering (ICME) framework.