Official Letter from Moses Isaak to Aaron Moses Dropsie, Amsterdam, August 4, 1819 An official letter written in Dutch by Moses Isaak in Amsterdam on August 4, 1819, concerning Aaron Moses Dropsie (1794-1839). The letter likely pertains to Dropsie's immigration to the United States. Dropsie arrived in Philadelphia on September 27, 1819, aboard the ship *Dido*. This letter is one of four personal and family documents related to Dropsie.