Landgraviate of Hesse-Darmstadt
When the Auheimer Mark (an old cadastral unit) was partitioned in 1786, Hainstadt was given part of the "Markwald" (common forest). After Electoral Mainz's Secularization, the "Oberamt" of Steinheim passed in 1803 to the Landgraviate of Hesse-Darmstadt. In 1882, the Hanau-Eberbach railway with a railway station in Hainstadt was opened.