" If you wanted to go on from the end of The Hobbit I think the ring would be your inevitable choice as the link. If then you wanted a large tale, the Ring would at once acquire a capital letter; and the Dark Lord would immediately appear. As he did, unasked, on the hearth at Bag End as soon as I came to that point. So the essential Quest started at once. But I met a lot of things along the way that astonished me. Tom Bombadil I knew already; but I had never been to Bree. Strider sitting in the corner of the inn was a shock, and I had no more idea who he was than Frodo did. The Mines of Moria had been a mere name; and of Lothlorien no word had reached my mortal ears till I came there.
-- (J.R.R. Tolkien to W.H. Auden, June 7, 1955.) "
― J.R.R. Tolkien , The Letters of J.R.R. Tolkien