Significance Copper, zinc superoxide dismutase 1 (SOD1) is an enzyme involved in free radical scavenging in the cell. Despite the high stability of the mature protein, mutations, covalent modifications, and increased populations of immature forms result in instability and misfolding of SOD1 that is neurotoxic. Here, we study how the structure and dynamics of SOD1 change as a function of maturation. We find that as SOD1 progresses to its final active conformation, the free-energy landscapes for each successive state along the maturation pathway appear to become smoother with less exploration of higher energy conformations. Our results suggest that maturation may occur via a series of steps in which the transiently populated structures of preceding states successively become the dominant conformations.