This presentation provides a look at the history of 4-H clubs and their relationship to the developing ideas about rural culture, community and modernity in 20th century United States. 4-H clubs—the youth phase of agricultural and home economics extension work—were central to the USDA’s program for rural modernization in the early decades of the 20th century. Cultivating “the country’s best crop,” as these young people were often described, was a matter of culture as well as agriculture, and 4-H club work sought to revitalize rural society alongside rural livelihoods. The biological metaphor of development—of crops, children, communities, and civilization—was central to these efforts, and 4-H’s work with rural youth in rural places illuminates a strand of thinking about development that relied on growth, guidance, and nurture to cultivate modernity on rural terms.