The Unification Church is the organization run by the Reverend Sun Myung Moon. Its members are often called Moonies. The Unification Church is considered to be a cult by most Christian organizations (I myself pass no judgement here).
The church began gaining followers in the late 50's, with the first group of American followers forming in Eugene, Oregon (they later moved to San Francisco).
Unification theology pivots on three events in history: Creation, the Fall, and Restoration. God created the world in six days as described in Genesis 1, though the days are not taken to mean literal twenty-four hour periods. Rather, they are seen as periods in God's creation. As an artist's character and nature are seen through his painting, so the character of the invisible God is seen through his creation. Thus, much can be learned about God by looking at his creation.
The Unification Church also owns The Washington Times.