This book examines the concept of the “folk” activated by the “Go to the Folks” movement through the lens of the 1920s cultural movement in China. By analyzing case studies such as Li Dazhao, Zhou Zuoren, Gu Jiegang, Yang Chengzhi, the journal China Youth, and the journal Folksong Weekly, it explores how the slogan “Go to the Folks” intersected with social thought, literature, historiography, folklore studies, ethnology, and party politics, revealing significance of this slogan as a movement of cultural reinvention. The “earthspring” in the title symbolizes the movement’s development as akin to subterranean springs: a convergence of countless underground streams that gather strength drop by drop and ultimately merge into a transformative current. The “Go to the Folks” movement redefined the scope of “folk” by foregrounding two critical dimensions: rural communities and ethnic minorities in border regions. These became central to conceptualizing the “folk” in subsequent discourse, while also laying the ideological and practical groundwork for the rise of “the people” (renmin) as a political force that would shake China and the world.