Jack London, The Scarlet Plague (1915)

It's not exactly a zombie novel, but it's definitely post-apocalyptic.   (Yes, and it's by that Jack London.)  For a return-to-the-stone-age work set in the ruins of San Francisco, I prefer Earth Abides by George Stewart, but this is still an interesting early twentieth century, return-to-savagery in a morally indifferent universe piece.   Full novel at Gutenberg here.


* * *

The old man peered from under his green leaf at the danger, and stood as quietly as the boy. For a few seconds this mutual scrutinizing went on; then, the bear betraying a growing irritability, the boy, with a movement of his head, indicated that the old man must step aside from the trail and go down the embankment. The boy followed, going backward, still holding the bow taut and ready. They waited till a crashing among the bushes from the opposite side of the embankment told them the bear had gone on. The boy grinned as he led back to the trail.

"A big un, Granser," he chuckled.

The old man shook his head.

"They get thicker every day," he complained in a thin, undependable falsetto. "Who'd have thought I'd live to see the time when a man would be afraid of his life on the way to the Cliff House. When I was a boy, Edwin, men and women and little babies used to come out here from San Francisco by tens of thousands on a nice day. And there weren't any bears then. No, sir. They used to pay money to look at them in cages, they were that rare."

"What is money, Granser?"

Before the old man could answer, the boy recollected and triumphantly shoved his hand into a pouch under his bear-skin and pulled forth a battered and tarnished silver dollar. The old man's eyes glistened, as he held the coin close to them.

"I can't see," he muttered. "You look and see if you can make out the date, Edwin."

The boy laughed.

"You're a great Granser," he cried delightedly, "always making believe them little marks mean something."

The old man manifested an accustomed chagrin as he brought the coin back again close to his own eyes.

"2012," he shrilled, and then fell to cackling grotesquely. "That was the year Morgan the Fifth was appointed President of the United States by the Board of Magnates. It must have been one of the last coins minted, for the Scarlet Death came in 2013. Lord! Lord!—think of it! Sixty years ago, and I am the only person alive to-day that lived in those times. Where did you find it, Edwin?"