The amparo suit is the most novel of Mexican legal institutions and a principal source of litigation before the federal courts. It serves to protect individuals from any law or act of public authority in violation of constitutionally guaranteed rights, and, by implication, provides a general judicial defense of constitutionality. Given its theoretical interest and practical importance, amparo is the subject of a voluminous literature. Barragán, contrary to most legal-historical opinion, argues that amparo derives directly from the residencia and its adaptations in the Cádiz Constitution of 1812 and the Mexican Federal Constitution of 1824. The argument is supported by a rather selective examination of the evidence, which demonstrates a number of similarities of intent and some of procedure, but is not, on the whole, completely persuasive. The book’s value lies in its detailed account of the application of the residencia to the conditions and requirements of constitutional government.