In 2014, the Danish school system celebrated its 200-year anniversary with a five-volume publication entitled "Dansk skolehistorie gennem 500 år" (500 years of Danish school history). As editors-in-chief, we took our inspiration from the cultural turn within history more generally and the search for the black box of schooling among historians of education more specifically. Our ambition was to write a history about how schooling was done, experienced, negotiated, and contested by a range of agents, from pupils to parents, teachers, and authorities. We wanted to write the history of education as intimately connected to and intertwined with changing childhoods and broader cultural and social developments. In addition, we decided to write from the perspective of diversity with regard to agents, contexts, schools, sources, and methodologies. Our approach is new within Danish educational history writing and as such not yet reflected in international work on the Danish school system. The purpose of this article is therefore to present our arguments, chronologies, and conclusions. The article also introduces our research design and a description of four methodological tools we found helpful when writing the history of education from a bottom-up perspective. The article ends by outlining our main conclusions and reflecting on the challenges we encountered when opening "the black box of schooling".