Nanoporous gold (NPG) thin films offer an opportunity to investigate the effects of nanoscale geometric confinement on the mechanical properties of metals. In the present study, NPG films supported by substrates were fabricated by dealloying Au-Ag films on Kapton and silicon. The microstructural evolution of NPG at various stages of dealloying was observed and analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Cracking occurred at grain boundaries during dealloying and may be exacerbated by pre-existing tensile stress in the film. Stress evolution of NPG films on silicon substrates during dealloying was measured with the wafer curvature technique and revealed an overall shift toward compressive stress.