We explain the process used at Kean University (New Jersey) to create an innovative undergraduate degree program in sustainability science. This interdisciplinary program provides students with the strong science background necessary to understand and address the opportunities associated with sustainability. We articulate seven steps taken during the first year of developing the major and three additional steps that explain its evolution. Sustainability is the primary focus of each course within the curriculum. By sharing our experiences, other institutions may be encouraged or assisted in developing a similar program.