Then there is the rare new look at this concept, which Rysa Walker has achieved in Timebound, her debut novel. Her protagonist, Kate (or perhaps Prudence), has experienced the changes of history as a helpless particle in the stream of time. Like everyone around her, one moment she has a firm memory and history of one kind, the next, her memory and the world's history have shifted completely. Unlike others around her, Kate can sense that something has happened.
When Kate learns that there is a technology to control time travel and retain one's memory of the history that pertained before a change was made, she must travel back to 1893 Chicago to save her family from the actions of a cabal of time saboteurs. In so doing, Kate must essentially play God by determining which history will be saved. And it is that decision, with her actions at the World's Columbian Exhibition, that make this novel so compelling.
There is an amazing book by Eric Larsen, Devil in the White City, that details the culture of the end-of-the-19th-century World's Fair in Chicago.
The story underlying the development of the Fair with its presentation of wonders (that today are commonplace) is told against the background of a serial killer who stalked young women at the fair, imprisoning, torturing and killing them.
Rysa Walker uses both of these stories, the killer and the debut of items like electric fair lighting, the Ferris wheel, and civic gardens, to drive her tale of sabotage, altered history and the triumph of love over time's arrow.
* Just off the top of my head:
- The ability to travel in time allows changes to history: Ray Bradbury's seminal 1952 short story A Sound of Thunder (which contributed to the concept of "butterfly effect")
- How such changes are prevented: my favorite is the short story by Alfred Bester, The Men Who Murdered Mohammed
- The need for time police to prevent disastrous changes to history: Keith Laumer's short story Delenda Est and H. Beam Piper's short novel Lord Kalvan of Otherwhen come to mind
- A future-time traveler in the past: Mark Twain's A Connecticut Yankee in King Arthur's Court; H.G Wells' The Time Machine; Heinlein's The Door Into Summer
- A past-time traveler brought to the future: Asimov's short story The Ugly Little Boy and novel Pebble in the Sky