The Forest Monster by Charles E. LaSalle

Or, Lamora, the Maid of the Canyon.
Horror story of a monster loose in the woods.  Thrilling tale for old and young alike.

Mad Music Science Fiction by Anthony Pelcher

Mad Music by Anthony Pelcher is a short tale about a building, and some lovers.... a strange, very strange story for true lovers science fiction short stories..

 

After London by Richard Jefferies

After some sudden and unspecified catastrophe has depopulated England, the countryside reverts to nature, and the few survivors to a quasi-medieval way of life. Beginning with a loving description of nature reclaiming England -- fields becoming overrun by forest, domesticated animals running wild, roads and towns becoming overgrown, the hated London reverting to lake and poisonous swampland -- the rest of the story is an adventure set many years later in the wild landscape.
The meadows were green, and so was the rising wheat which had been sown, but which neither had nor would receive any further care. Such arable fields as had not been sown, but where the last stubble had been ploughed up, were overrun with couch-grass, and where the short stubble had not been ploughed, the weeds hid it.

Jefferies’ novel can be seen as an early example of post-apocalyptic fiction. After some sudden and unspecified catastrophe has depopulated England, the countryside reverts to nature, and the few survivors to a quasi-medieval way of life.

The first part, The Relapse into Barbarism, is the account by some later historian of the fall of civilisation and its consequences, with a loving description of nature reclaiming England. The second part, Wild England, is an adventure set many years later in the wild landscape and society.

The book is not without its flaws but is redeemed by the quality of the writing, particularly the unnervingly prophetic descriptions of the post-apocalyptic city and countryside. 

The Golden Slave by Poul Anderson

This might have happened. The Cimbri are still remembered by the old district name Himmerland. Plutarch describes the battle at Vercellae, which took place 101 B.C., and its immediate aftermath. Other classical writers, such as Tacitus and Strabo, and a treasure of archeological material enable us to guess at the Cimbri themselves. Apparently they were a Germanic tribe from Jutland, with some elements of Celtic culture; by the time they reached Italy they had grown into a formidable confederation.

The Cimbrian hordes galloped across the dawn of history and clashed in screaming battle against the mighty Roman legions.Led by their chief, Boierik, and his son, Eodan, the hungry and homeless pagan tribes hurled back the Romans time after time in their desperate search for land. But for all the burning towns, the new-caught women weeping, the wine drunk, the gold lifted, the Cimbri did not find a home. And now it was over. At Vercellae the Roman armies shattered them completely. Only a few survived—and for them death would have been more merciful.​ Eodan, the proud young chieftain, had been caught and sold into slavery, his infant son murdered and his beautiful wife, Hwicca, taken as a concubine.

But whips and slave chains could not break the spirit of this fiery pagan giant who fought, seduced and connived his way to a perilous freedom to rescue the woman he loved.

Black Man's Burden by Dallas McCord Reynolds

The turmoil in Africa is only beginning—and it must grow worse before it's better. Not until the people of Africa know they are Africans—not warring tribesmen—will there be peace....A strange tale of a possible future.  This is a thrilling tale of science fiction and possiblities by Dallas McCord Reynolds.

The Syndic by C. M. Kornbluth

A classic, full-length novel of a possible future: mob rule in the USA.