It's surprising what comes up.
Mark Twain, for instance, has knights of the Round Table out selling barbed wire as part of a push to civilize England (A Connecticut Yankee at King Arthur's Court, 1889):
. . . their penchant for wandering, and their experience in it, made them altogether the most effective spreaders of civilization we had. They went clothed in steel and equipped with sword and lance and battle-axe, and if they couldn’t persuade a person to try a sewing –machine on the installment plan, or a melodeon, or a barbed-wire fence, or a prohibition journal, or any of the other thousand and one things they canvassed for, they removed him and passed on.
And a character in James Joyce's 1922 Ulysses, after thinking for a while about advertising, makes a startling suggestion about the origin of barbed wire:
A procession of whitesmocked men marched slowly towards him along the gutter, scarlet sashes across their boards. Bargains. . . . Doesn't bring in any business either. I suggested to him about a transparent show cart with two smart girls sitting inside writing letters, copybooks, envelopes, blotting paper. I bet that would have caught on. Smart girls writing something catch the eye at once. Everyone dying to know what she's writing. . . . Wouldn't have it of course because he didn't think of it himself first. Or the inkbottle I suggested with a false stain of black celluloid. His ideas for ads like Plumtree's potted under the obituaries, cold meat department. You can't lick 'em. What? Our envelopes. Hello! Jones, where are you going? Can't stop, Robinson, I am hastening to purchase the only reliable inkeraser Kansell, sold by Hely's Ltd, 85 Dame Street. . . . That was a nice nun there, really sweet face. Wimple suited her small head. Sister? Sister? I am sure she was crossed in love by her eyes. Very hard to bargain with that sort of woman. . . . It was a nun they say invented barbed wire.
From the beginning, barbed wire has been used to control both man and beast, so it's not surprising to think that a pedagogical nun might have invented it. In fact, it's downright funny. Later in the novel, the connection between religion and barbed wire is enhanced:
what do we lack with your barbed wire? crucifix not thick enough?
Flannery O'Connor's 1952 novel Wise Blood continues in this ascetic religious vein when Hazel Motes wraps himself in barbed wire after blinding himself to prove himself worthy.
So what does barbed wire mean? We're working that out, step by slow step, but it obviously has to do with how the wire is used in literature and advertising and not just with how it was used on the range.