 Today's community of Westerngrund mainly comprises areas that belonged to the Schönborn "Amt" of Krombach, which in 1806 was mediatized with the newly formed Principality of Aschaffenburg, with which it passed in 1814 (by this time it had become a department of the Grand Duchy of Frankfurt) to the Kingdom of Bavaria.In the course of administrative reform in Bavaria, the current community came into being with the "Gemeindeedikt" (“Municipal Edict”) of 1818.Within community limits in 1970, 1,454 inhabitants were counted, in 1987 1,584 and in 2000 1,918.