Short answers, pulled from the story.
J. R. R. Tolkien named H. Rider Haggard's 1887 adventure novel She: A History of Adventure as his only personal favorite during a 1966 interview. He described how this story interested him as a boy and compared it to the Greek shard of Amyntas which acted as a machine to set everything in motion.
H. G. Wells's description of the subterranean Morlocks in his 1895 science fiction novel The Time Machine appears suggestive of the character Gollum. Scholars also note direct resonances between the monstrous Gollum and the evil ancient hag Gagool from Haggard's 1885 novel King Solomon's Mines.
William Morris prose romances shaped Tolkien's stylistic choices and provided placenames like the Dead Marshes and Mirkwood directly from his writings. Marjorie Burns writes that Bilbo Baggins matches Morris's account of travels in Iceland in the early 1870s including details about ponies and a boisterous Beorn-like man called Biorn the boaster.
J. R. R. Tolkien derived the phrase crack of doom from an unnamed story by Algernon Blackwood found in his 1909 novel The Education of Uncle Paul. This concept attracted Tolkien because of his interest in travelling back in time through such cracks described as a gap between Yesterday and To-morrow.
Postwar literary figures such as Anthony Burgess, Edwin Muir and Philip Toynbee heavily criticized The Lord of the Rings while others like Naomi Mitchison and Iris Murdoch respected the work. The poet W. H. Auden championed it and Anna Vaninskaya argues its form fits into the romantic tradition of writers like W. B. Yeats.