For over 300 years beginning in 1555, the Jewish population was cloistered without rights in the Roman Ghetto. Nearly 3,500 people were forced to live in the cramped, walled-in and filthy quarters measuring less than 7.5 acres. Their harsh, segregated treatment was reversed when the Papal States became part of the Kingdom of Italy in 1870. In response to their new freedom and citizenship, the Jews destroyed the ghetto walls and dilapidated structures while rebuilding decent apartments. They also constructed the Great Synagogue of Rome in 1904. In the lower level of the Orthodox Judaism temple is the Jewish Museum of Rome. The exhibits tell the stories of over two millenniums of Jewish history in the city.