Was wicca big in the 1970?

Modern Wicca originated in the United Kingdom (i.e. Great Britain/The British Isles) in the late 1920's and early 1930's. It wasn't brought over to the U.S. until the late 1960's and early 1970's most notably by Wiccan author Raymond Buckland. So, no, it wasn't particularly popular at that time. It isn't exactly "big", now, for that matter, when compared to other religions, such as Christianity or Buddhism... even though it is a rapidly growing religion; it is still quite in a state of infancy... in other Words, it is not currently a mainstream religion.