Simplify the following text for a Grade 7 native English-speaking person.
Original: It was made a municipality by the Haitian government in 1843 . After the Dominican independence in 1844 , Hato Mayor was not a municipality until 1848 when it was made one in the El Seibo province .
Simplified: Until July 1843 , Hato Mayor del Rey was part of the community of El Seibo and the province of El Seibo .