Mexico has had a Jewish population since the early Colonial Era. However, these early individuals could not openly worship as they were persecuted by the Spanish Inquisition for practicing Judaism. Independent Mexico eventually adopted freedom of religion and began receiving Jewish immigrants, many of them refugees. The book has records of almost 18,300 who emigrated to Mexico between 1900 and 1950. Most (7,023) were Ashkenazi Jews whose ancestors had settled in Eastern Europe, mainly Poland. A further 2,640 Jews arrived from either Spain or the Ottoman Empire and 1,619 came from Cuba and the United States.