The purpose of this paper is to provide a historical overview of what was known about oil shale in Estonia in the 19th century and reveal some background political and economic processes in this country, Russia and the world as a whole that framed oil shale studies in those days. We specify how oil shale was rediscovered in Kohala estate by Gregor von Helmersen in 1838. We also bring to light how oil shale was independently detected by Paul Georg Alexander Petzholdt in 1850. Finally, we describe the peculiar chain of events that led to oil shale studies and usage on Kukruse estate in the 1870s.