The Wealth of Nations by Part 1 Chapter 10 Page 65

By the 5th of Elizabeth, commonly called the Statute of Apprenticeship, it was enacted, that no person should for the future exercise any trade, craft, or mystery at that time exercised in England, unless he had previously served to it an apprenticeship of seven years at least; and what before had been the bye law of many particular corporations became in England the general and public law of all trades carried on in market towns.

For though the words of the statute are very general, and seem plainly to include the whole kingdom, by interpretation its operation has been limited to market towns, it having been held that in country villages a person may exercise several different trades, though he has not served a seven years’ apprenticeship to each, they being necessary for the conveniency of the inhabitants, and