Origin of the phrase “close to the bone”
Instances of "close to the bone" in a literal sense go back at least as far as 1708. From the entry on "Bones" in John Harris, Lexicon Technicum: or An Universal English Dictionary of Arts and Sciences, second edition, volume 1 (1708):
The inner Superficies of the Periosteum sticks as close to the Bone as if it were glued to it ; and besides, the Periosteum has little Fibrillæ or Threads continued from it, that enter into the Substance of the Bone, which gives them (probably) some internal Sense.
And similarly, from Nathan Bailey, Dictionarium Rusticum, Urbanicum & Botanicum: or A Dictionary of Husbandry, Gardening, Trade, Commerce, and All Sorts of Country-Affairs, third edition, volume 1 (1726):
EXCRETION-BONEY ; an evil incident to Horses, occasion'd mostly by Causticks, or burning Corrosives, unduely put to Wounds that lie close to the Bone, as when the Wound is in the Leg, or about the Pasterns; for the Flesh being much burned by them, causes an Excrescence to grow upon the Bone, which by the little Experience of the Farrier is healed, but the Excretion remains; and sometimes it comes by a Shackle, or the galling of a Lock, or Fetters that have been long continued upon the Foot. What is proper for the Bone-Spavin, likewise cures this.
Figurative or poetic use "close to the bone" appears at least as early as Henry David Thoreau's poem "The Old Marlborough Road" (1850), reprinted in Collected Poems of Henry Thoreau (1943):
O man of wild habits, / Partridges and rabbits, / Who hast no cares / Only to set snares, / Who liv'st all alone, / Close to the bone, / And where life is sweetest / Constantly eatest.
From Oliver Wendell Holmes , "My Search for 'The Captain'" (1863), in Soundings from the Atlantic (1864):
A feeble, attenuated old man, who wore the Rebel uniform, if such it could be called, stood by without showing any sign of intelligence. It was cutting very close to the bone to carve such a shred of humanity from the body politic to make a soldier of.
And from Charles Van Zandt, "Commemorative Address Spoken Before the Rhode Island Society for the Encouragement of Domestic Industry" (January 19, 1870):
If you doubt this [the need for industry, intelligence, and morality in defense of Rhode Island's interest"] to-day, it will be irresistibly forced home upon you to-morrow, and you will learn how very close to the bone the unconscious tooth of humanity is always gnawing.
It is interesting that all three of the earliest examples of figurative use of "close to the bone" that I found are from New England sources. However, the number of instances is so small that it is impossible to draw any firm conclusion about the probable geographic origin of the phrase from those examples.