This book is one of the earliest attempts to assemble a systematic classification of America's indigenous languages. It focuses mainly on the connection between culture, grammar, and vocabulary. It addresses the different theories of the roots of the American race and the archaeological proof of the existence of humans in America. It examines geologists' views and America's physical geography in reference to Europe. It considers the physical aspects of the Native Americans, their culture, religion, domestic practices, and family organization, delivering a broadly anthropological and historical context for the linguistic work. The author gave special attention to the parts of the continent, especially south of Mexico, whose ethnography was unheard of at the time of writing. Each chapter of this work covers a specific region, and the book contains a detailed linguistic appendix.