"An Inquiry into the Nature and Causes of the Wealth of Nations" by Adam Smith is a treatise published in 1776. This foundational work of classical economics examines what builds nations' wealth at the dawn of the Industrial Revolution. Smith introduces revolutionary concepts like division of labor, free markets, and the "invisible hand" of self-interest guiding economic activity. Challenging the mercantilist policies of his era, he argues that supply and demand should determine commerce rather than government regulation, establishing theoretical foundations that would shape economic thought for centuries.