Business firms are ubiquitous in modern society, but an appreciation of how they are formed and for what purposes requires an understanding of their legal foundations. This book provides a scholarly and yet accessible introduction to the legal framework of modern business enterprises. It explains the legal ideas that allow for the recognition of firms as organizational "e;persons"e; having social rights and responsibilities. Other foundational ideas include an overview of how the laws of agency, contracts, and property fit together to compose the organized "e;persons"e; known as business firms. The institutional legal theory of the firm developed embraces both a "e;bottom-up"e; perspective of business participants and a "e;top-down"e; rule-setting perspective of government. Other chapters in the book discuss the features of limited liability and the boundaries of firms. A typology of different kinds of firms is presented ranging from entrepreneurial one-person start-ups to complex corporations, as well as new forms of hybrid social enterprises. Practical applications include contribution to the debates surrounding corporate executive compensation and political free-speech rights of corporations.