The freedom of religion: one of the cornerstones of the American Constitution granting everyone to choose and exercise their beliefs freely without dictating an official state-endorsed religion. Considering the country’s history, this attitude has played a very important role in how the US has got to its current status and not merely from a religious point of view but from other - demographic and social - aspects as well: this freedom has not only gave opportunities to believers but to those providing something to believe in. The US has become a paradise for persecuted groups: they could build from sketch without disturbing the already well-established churches. This has led to the birth of a great number of cities which on one hand were built on the basis of certain churches as well as on religious tolerance. Even though the state itself has never endorsed any religion, there is a curious phenomenon arising: despite the tendency that in developed nations religion loses its importance, in the US it managed to upkeep its significance: 60% of Americans say religion is very important in their lives whereas in other developed countries - like in Germany or in Great Britain - this number hardly reaches 30% (“Pew Research Center”). The 85% of the American population who are believers can choose from 220 different churches. Most of them are various Christian denominations but there are also Islamic, Muslim and Jewish groups. In this essay I am trying to display the religious diversity of the US by describing the most important groups and denominations on the basis of how they contributed to the foundation of certain states, regions and cities. Christianity arrived into the US in the 16th-17th century as various nationalities brought their religions with them. These immigrants were mostly Protestants who came from Great Britain but there were people from France, Germany, Holland, Sweden and Ireland whose majority were Catholics. In fact several of the 13 colonies were established by settlers who wished to exercise their faith undisturbed and without being discriminated. The era following the Protestant Reformation had a huge effect on the Americas. In the 17th-19th century many people fled to the United States to avoid persecution. America promised to be ideal for establishing new churches as well as keeping up older ones which could not stand a chance to survive in their original sources. First, I am going to talk about churches which were brought in the US and then about one which was already established in the States. Probably the most well-known group of people associated with the early history of the US are the Pilgrim Fathers. These people similarly to the Puritans wished to purify the Anglican Church in England but as opposed to them, the Pilgrims wanted to separate from the Church of England. The Separatist Congregation was persecuted in England and left the country first to Amsterdam and then to Leiden in Holland in 1609. After having identity issues and difficulties to adapt to the country, in 1619 the Congregation obtained a land patent from the London Virginia Company and in 1620 they arrived to the mouth of the Hudson River on board of the ships Mayflower and Speedwell. They named their newly founded city Plymouth Colony in the honour of the city in England where they started their journey. Religion played an important part in the colony’s legal and social systems and became the source of the notion of freedom of religion. The Separatists’ religious practises differed from the Puritan's. They were far less strict and membership required less devotion. Although it became the second most successful colony in the New England region right after Jamestown, ultimately it was annexed by the Massachusetts Bay Colony in 1691. In spite of its short life, the colony contributed much to the American folklore for example being the source of the tradition of Thanksgiving. Many Puritans arrived from England and they founded the Massachusetts Bay Colony which consisted of today’s cities Salem and Boston. It developed from the Massachusetts Bay Company founded by English Puritan businessmen who initiated the project in the hope that it would grow into a future profit-making endeavour. In the 1630s more than 20.000 people migrated to the area from England. The society of the bay was heavily influenced by religion; one could only become a freeman (a full member of the community) if next to being a stockholder they were also full members of the church (not simply by owning land as in other colonies). The Puritans of Massachusetts were Calvinist but had emphasis on different points. They believed that the people of the Earth were condemned to damnation and only a few - the Elects - could reach salvation. Their intent was to found a pure Godly colony of believers but this was a very strict covenant to fulfil and those who failed faced serious punishment. With time, it resulted in the extensive decrease o