Atlas Shrugged is a novel by Ayn Rand, first published in 1957 in the United States. Rand's fourth and last novel, it was also her longest, and the one she considered to be her magnum opus in the realm of fiction writing.
The book explores a dystopian United States where leading innovators, ranging from industrialists to artists, refuse to be exploited by society leading to the ironic circumstance of millionaires going on strike. The only clue to this strange circumstance is the enigmatic question "Who is John Galt?" which turns out to be a significant foreshadowing of the book's premises. The protagonist, Dagny Taggart, sees society collapse around her as the government increasingly asserts control over all industry (including Taggart Transcontinental, the once mighty transcontinental railroad for which she serves as the Vice President of Operations), while society's most productive citizens, led by this mysterious John Galt, progressively disappear. Galt describes the strike as "stopping the motor of the world" by withdrawing the "minds" that drive society's growth and productivity. In their efforts, these people "of the mind" hope to demonstrate that a world in which the individual is not free to create is doomed, that civilization cannot exist where every person is a slave to society and government, and that the destruction of the profit motive leads to the collapse of society.
Source: Wikipedia, "Atlas Shrugged", available under the CC-BY-SA License.