William Smith was born at Churchill, Oxfordshire in 1769. The son of the village blacksmith, Smith was the eldest of five children.
After elementary education at the village school, where he developed a liking for geometry and drawing, he decided to teach himself the skills of surveying, possibly because there were an increasing number of openings for that profession.
At the age of 18 he was employed by Edward Webb, a surveyor in Stow-on-the-Wold, and subsequently, in 1791, he set up in business on his own.
As a boy, Smith had developed an interest in the exposures of rock and the fossils which were to be found locally. As an adult, his surveys of land for canals and for the sources of building stone and coal in other parts of England led to a great increase in his knowledge and awareness of various geological features.
As he travelled, he found the strata he was familiar with in the south of England were repeated in other areas, with some outcrops stretching right across the country.
Coal miners were already aware of the occurrences of regular successions of workable coal seams. But on a larger scale, Smith began to recognise that sedimentary rocks could be identified by the fossils they contained, and that these rocks were always arranged in the same order.
Smith's discovery that beds of similar lithology can be distinguished by the assemblage of fossils in them was a concept virtually unrecognised by geologists of that period. Working on this principle, Smith was able to draw up a table of successive strata which could be applied in any other locality—an early version of the geological column.