I agree that much was going on before the 1950 but how much was intellectual vs. a true religious belief.
By the early 18th century, we had books on modern druids, druid orders, and Alexander Pope's rip-off of Virgil's Aeneid linking the modern druids to Troy. Mysticism, theosophy, eclectic ceremonial magic traditions used by particular orders, and more were all around before Wicca. Gardner actually was a part of the O.D.O.
However, except for the German
Völkisch movement, which began before the Nazi's and consisted largely of a religious/ideological "mythology" and functioned like a sick, twisted version of the nationalistic tendencies behind modern druidry, and the Nazi party's use of this movement along with pseudo-Aryan motifs and occult traditions, the "paganism" of the 19th and early 20th century was artistic (poetry, paintings, stories, etc.). And the modern Germanic (neo)pagans have nothing in common with
Die völkisch-religiöse Bewegung im Nationalsozialismus (the main title of Puschner, U. (2012).
Die völkisch-religiöse Bewegung im Nationalsozialismus: eine Beziehungs-und Konfliktgeschichte (Vol. 47). Vandenhoeck & Ruprecht GmbH KG.).
True, there are still racist anti-Semites who sport tattoos of Nazi iconography and shaved heads,
Der Übermensch who survive to protect an ideology they don't understand and a philosophy they don't know of because most are probably incapable of reading, let alone reading Nietzsche.
These are pseudo-pagans (and imbeciles), not (neo)pagans. Ásatrú is a different story. But it began in the 70s, not the 50s. In the 50s, we barely had Wicca, and 2 decades later we not only had multiple
kinds or
types of Wicca, but different types of witches who did not identify themselves as Wiccans. The revival of (neo)Gnosticism was also later than the 50s.
Modern paganism has more to do with things like Jungian psychoanalysis, armchair anthropology of the 19th century, the literature of Shelley, Graves, etc., and the mythology collections that inspired countless authors and artists. Equally important was the death of a Christianity so ingrained in Western culture that much of it survives simply because people (especially Americans) are not prone to trying to understand their cultural heritage. There are still plenty of Christians, but there is not any Christian west, and therefore there is no unified identity that there used to be. Like psychoanalysis, positive psychology, and ideology (political, environmental, racist, whatever), modern paganisms filled a void. The numinous, as it were.
Well from this it is clear the recovery of paganism has a longer history than I was completely aware of.
Modern Hinduism and Buddhism are for the most part the result of an West-East interaction beginning several centuries ago.