The Night of the Trolls was the first of Keith Laumer's popular Bolo stories, a short novella introducing the Bolo Mark II and III. Although the Bolo stories eventually developed to the point that the Bolo tanks themselves became the main character of many stories, in the earliest stories the Bolos are just machines, albeit machines capable of carrying out quite complex programs.
The story itself follows an astronaut, known simply as Jackson, who was taking part in suspended animation experiments when... something happened. He wakes up 80 years later, to find the base deserted and his old town abandoned except for roving bands of half-feral humans. And a big honking tank, of course. He eventually hunts down the local 'Baron', who is living in splendor harvested from the ruins, and who is also hoping to take of some of the neighboring baronies (and perhaps even re-unite America!) with the help of his own captive Bolo. I cannot tell you more without giving away spoilers, except to say that this is one of Keith Laumer's traditional lone-man-takes-on-the-world stories.
As a stand-alone story (or even part of a collection) this isn't a particularly interesting tale by today's standards. Being abandoned in suspended animation may have been a new idea when the story was published, but it isn't now. While big tanks are always exciting they can carry a story only so far, and the exciting state-of-the-art juggernauts of the 1950s are not so impressive in 2011. The bulk of the story consists of Jackson being wily and tough, and the tone is much apiece with Keith Laumer's other writings, which have a strong theme of survival-against-all-odds. It is a good read if you are a Laumer fan, and an okay read for a classic science fiction fan. It is, of course, of some historical interest, as the Bolo stories have inspired dozens of SF authors to add to the Bolo mythology in later collections.
The Night of the Trolls was first published in the 1953 anthology Worlds of Tomorrow, edited by August Derleth. It has also appeared in the collections Bolo: Annals Of The Dinochrome Brigade in 1976 and The Compleat Bolo in 1990, both collections of Keith Laumer's Bolo stories.
The story can be found on-line here.