Johann was born in 1761, the son of Andreas Sanftleben and his wife, Lucia Tiedermann.  Johann, his wife Anna Dorthea Kruedener, and their three children lived in the village of Ritzbuettel, adjacent to the town of Cuxhaven on the coast of the North Sea. 

Family records indicate that Andreas Christoffer was a blacksmith, who, although he did shoe horses, really made his living crafting a variety of specialty chains, farm tools, and other implements, especially marine products for the merchant fleet.