There is religious freedom in the United States, and the overwhelming majority of Americans are Christians. In turn, the majority of Christians are Protestants, but of many denominations. The largest single Christian group embraces members (some 61 million in 1999) of the Roman Catholic Church; the Orthodox Eastern Church is also represented. In addition, roughly 2.5% of Americans adhere to Judaism, and some 1%–2% are Muslims. Education in the United States is administered chiefly by the states. Each of the 50 states has a free and public primary and secondary school system. There are also in the United States more than 3,500 institutions of higher learning, both privately supported and state supported (see separate articles on individual colleges and universities).