The Wealth of Nations
An Inquiry into the Nature and Causes of the Wealth of Nations is the magnum opus of the Scottish economist Adam Smith, published on March 9, 1776, during the Scottish Enlightenment. It is a clearly written account of political economy at the dawn of the Industrial Revolution, and is widely considered to be the first modern work in the field of economics. The work is also the first comprehensive defense of free market policies. It is broken down into five books between two volumes. The Wealth of Nations was written for the average educated individual of the 18th century rather than for specialists and mathematicians.
There are three main concepts that Adam Smith expands upon in this work that forms the foundation of free market economics: division of labour, pursuit of self interest, and freedom of trade.