Great Britain's formal acknowledgment of the United States' sovereignty at the end of the American Revolutionary War. In the original 13 colonies, most laws contained elements found in the English common law system. The vast majority of the Founding Fathers of the United States were of mixed British extraction. Most of these were of English descent, with smaller numbers of those of Scottish, Irish or Scots-Irish, and Welsh ancestry. A minority were of high social status and can be classified as White Anglo-Saxon Protestant (WASP). Many of the prewar WASP elite were Loyalists who left the new nation. Immigration after 1776 Nevertheless, longstanding cultural and historical ties have, in more modern times, resulted in the Special Relationship, the exceptionally close political, diplomatic and military co-operation of United Kingdom – United States relations. Linda Colley, a professor of history at Princeton University and specialist in Britishness, suggested that because of their colonial influence on the United States, the British find Americans a "mysterious and paradoxical people, physically distant but culturally close, engagingly similar yet irritatingly different". For over two centuries (1789-1989) of early U.S. history, all Presidents with the exception of two (Van Buren and Kennedy) were descended from the varied colonial British stock, from the Pilgrims and Puritans to the Scotch-Irish and English who settled the Appalachia. Cultural contributions Much of U.S. culture shows influences from nation states of British culture. Colonial ties to Great Britain spread the English language, legal system and other cultural attributes. Historian David Hackett Fischer has posited that four major streams of immigration from the British Isles in the colonial era contributed to the formation of a new American culture, summarized as follows: East Anglia to New England - The Exodus of the English Puritans (Pilgrims and Puritans influenced the Northeastern United States' corporate and educational culture) The South of England to the lowland South - The Cavaliers and Indentured Servants (Gentry influenced the Southern United States' plantation culture) Northern England to the Delaware Valley - The Friends' Migration (Quakers influenced the Middle Atlantic and Midwestern United States' industrial culture) The Scottish Lowlands to the Backcountry - The Flight from North Britain (Scotch-Irish, of lowland Scottish and border English descent, influenced the Western United States' ranch culture and the Southern United States' common agrarian culture) Fischer's theory acknowledges the presence of other groups of immigrants during the colonial period, both from the British Isles (the