Seed Savers Exchange is a small non-profit that's making a big difference. For a half century, they've been saving seeds, getting them out into gardens, telling their stories––and cultivating biodiversity that has been badly diminished with the rise of corporate agriculture and seed production.
Located in Decorah, Iowa, Seed Savers has a large farm where they cultivate genetic diversity, including vegetables, flowers, fruits, and even heritage livestock. You can get and share seeds through their exchange and their seed catalog.