The document provides a history of the development of public relations. It discusses how PR has evolved from early uses of persuasive communication by leaders to shape public opinion, to the modern practice of two-way communication, research, and strategic planning. Key developments included the professionalization of PR in the 1920s in the US, the growth of PR's role in politics and nation-building in the 20th century, and the rise of PR agencies and in-house corporate PR departments. The document also summarizes models of PR, such as press agentry, public information, two-way asymmetric, and two-way symmetric.