Most commonly used to refer to the Episcopal Church or the Protestant Church in the United States of America. It is the National Church of the United States and a part of the Anglican Communion. The Episcopal Church has a membership of approximately 2.3 million and more than a quarter of all Presidents were Episcopalian. The Washington National Cathedral is an Episcopal Cathedral. The roots of the colonization, founding, leadership, and growth of the United States of America are very closely tied to the Episcopal Church.
Unlike many churches of similar liturgical background, the Episcopal Church allows ordained priests to be married, and the church ordains women (at every level, ie. Deacon, Priest, and Bishop).
Many consider the Episcopal Church to follow the via media or "middle way" between Protestant and strictly Catholic practices. Indeed, the Episcopal liturgy explicitly affirms belief in "one holy apostolic" church. Thus, many Episcopalians will argue that Roman Catholics are not the only "Catholics," but rather represent one of three branches of Catholicism--the Eastern Orthodox, the Roman Catholic, and the Episcopal or Anglo-Catholic. Episcopal liturgy, or the practice of the people in worship, does resemble that of the Roman Catholic Church, with certain differences, most notably the use of the Book of Common Prayer. -wikipedia
The Episcopal Church is highly involved in mission work around the world, has a particularly large number of congregants in Africa, where the church raises money to fight poverty, disease, and oppression.
The three tenets of the Anglican church, which have carried on into the Episcopal Church are Scripture, tradition, and reason, thus showing that the church is based strongly on the idea of being an informed, thinking participant in one's faith.