The book "Proceedings of the Fourth National Conservation Congress in Indianapolis, October 1-4, 1912" is a collection of documents in which the participants of the meeting discussed issues of environmental protection and natural resources. The authors of this book are representatives of the United States. National Conservation Congress, which made a significant contribution to the development of concepts and strategies aimed at preserving biodiversity and balanced use of natural resources. This publication is a valuable source of information for the study of the history and development of nature conservation in the United States of America in the early 20th century.