The Map That Changed the World is the story of how geology became an important and respected science. The author, Simon Winchester, traces the story of William Smith, a canal digger who realized the fossils he found could be used to learn more about the makeup and history of the Earth. His work led to the formation of modern geology.

William Smith's life is examined in great detail in regard to his work. The man who created the first geological map of England didn't get thanked for it right away. Instead, he was shunted to the edges of society and left to live without money or even a home at times. Geology wasn't a respected or understood thing while he was working on his initial findings. Winchester writes:

But all such assumptions were to be assaulted, and shockingly so, before the next hundred years were out. To no small degree it was to be William Smith’s geological findings, along with a raft of other discoveries, that were to change things. His findings were to prove vitally important in triggering the collision that was eventually to take place between the religious beliefs that were in the ascendant at the time and the scientific reasoning that would provide the spur for the intellectual activities of a century later.

He created the underpinnings for the entire discipline as he dug canals, found fossils, and then began to follow his findings throughout the country. Winchester talks about the social and religious beliefs in England at that time to show why people like Smith had a better chance of living longer and doing good scientific work than they would have in the past.

When Smith was fired from his job—which was reliable and paid well—he had a difficult time coming back from that. Winchester says:

Except that in retrospect there appears to have been more than a touch of hubris about him. For below the surface matters were beginning, if slowly, to unwind. His financial affairs were starting to unravel. Those who would eventually come to cheat him, and try to deprive him of the honors he was rightly due, were beginning to gather, and to circle. He would never have full-time, fixed employment again—his six years with the canal company marked the summit of his career as a company man. From now on he would be in the perilous position of the freelance mineral surveyor, earning as much as his wits and his contacts might bring him.

He continued to work on his map for years after he was let go from working on canals. While he worked, though, other people took note of his ideas and started to figure out that they could steal those ideas. Though Smith was warned about this potential theft, he didn't take steps to secure his own intellectual property. Friends recommend that he print and publish his findings but he chose not to do that repeatedly.

For years, he was taken advantage of. He was even forced to sell a valuable fossil collection he'd kept over the years. However, his first love was still his work; he cared about what he was doing. This persistence, along with his major contributions to science, led to him being honored by the Geological Society of London. Winchester writes:

As everyone might wish, nothing but goodness seems to have attended the last years of William Smith’s life. He moved from Hackness to his cottage in Scarborough, he cultivated a small garden, he read and tried (in vain) to write the story of his own life, he nursed his now-fast-fading wife, he went...