the origin of hobbits

[Niere-Teleliniel]

Good question Susan! I searched a bit and found this:

JRRT tells us this in his "Letters" p. 158 footnote which I paraphrase for brevity:
The Hobbits are meant to be a branch of the human race, not dwarves or elves. Hence the two kinds can live together as they do in Bree, calling themselves the Big Folk and the Little Folk. They have no non-human "powers" but are more in touch with nature such as the soil, plants, and animals. Abnormally for humans, they are free from ambition or the greed for wealth. They are small, half human stature and dwindling with the passing of years. The size is partly to exhibit the pettiness of plain, unimaginative, parochial man. The other reason is to show, in creatures of very small physical power, the amazing and unexpected heroism of ordinary men "at a pinch".

Regarding the origin of hobbits, The Tolkien Companion refers you to The Red Book of Westmarch, which I unfortunately do not own a copy of.