What is the title of the book written by Adam Smith that defended free-market economies?

The book that defends free-market economies is "The Wealth of Nations," written by Adam Smith and published in 1776. This seminal work is a foundational text in classical economics, where Smith lays out his ideas about the benefits of a competitive market, the concept of the "invisible hand" guiding economic activity, and the importance of individual self-interest in promoting societal wealth.

Smith argues that when individuals are allowed to pursue their economic interests freely, they inadvertently contribute to the overall economic well-being of society. This is in stark contrast to works like "The Communist Manifesto," which advocates for a classless society and collective ownership, and "Das Kapital," which critiques capitalism itself. Meanwhile, "Principles of Political Economy" by John Stuart Mill, although influential, does not primarily focus on the defense of free-market economies in the same manner as Smith's work. "The Wealth of Nations" remains a crucial reference point for understanding economic principles related to capitalism and free markets.