The Indigenous Languages of the Americas takes stock of what is known about the history and classification of these languages and language families. It identifies the gaps in knowledge and puts them into perspective, and it assesses differences of opinion. It also resolves some issues and makes new contributions of its own.

The nine chapters of the book deal incisively with the major themes involving these languages: the classification and history of the Indigenous languages of North American, Middle American (Mexico and Central America), and South American; difficulties involving names of the languages; origins of the languages of the New World; unclassified, phantom, fake, and spurious languages in the Americas; recent hypotheses of remote linguistic relationships; the linguistic areas of the Americas; contact languages, including pidgins, lingua francas, and mixed languages; and loanwords and other new words in the native languages of the Americas.