As a form of Western esotericism, the New Age drew heavily upon a number of older esoteric traditions, in particular, those that emerged from the occultist current that developed in the eighteenth and nineteenth centuries. Such prominent occultist influences include the work of Emanuel Swedenborg and Franz Mesmer, as well as the ideas of Spiritualism, New Thought, and Theosophy. A number of mid-twentieth century influences, such as the UFO religions of the 1950s, the counterculture of the 1960s, and the Human Potential Movement, also exerted a strong influence on the early development of the New Age. The exact origins of the phenomenon remain contested, but there is general agreement that it became a major movement in the 1970s, at which time it was centered largely in the United Kingdom. It expanded and grew largely in the 1980s and 1990s, in particular within the United States. By the start of the 21st century, the term "New Age" was increasingly rejected within this milieu, with some scholars arguing that the New Age phenomenon had ended.