Simplify the following text for a Grade 9 native English-speaking person.
Original: In 1977 in the course of municipal reform in Hesse , the neighbouring communities of Froschhausen and Klein-Welzheim were merged into Seligenstadt .
Simplified: The city consists out of the town Seligenstadt and the 2 former independent villages Froschhausen and Klein-Welzheim , both now urban districts of Seligenstadt . On 1 January 1977 they were united .