From October 2 to November 20, 2017, a working group of individuals representing multiple NDSA member institutions and interest groups conducted a survey of organizations in the United States actively involved in, or planning to start, programs to archive content from the Web. This effort builds upon and extends a broader effort begun in three earlier surveys, which the NDSA Web Archiving Survey working group has conducted since 2011.The goal of these surveys is to better understand the landscape of Web archiving activities in the United States by investigating the organizations involved; the history and scope of their Web archiving programs; the types of Web content being preserved; the tools and services being used; access and discovery services being offered; and overall policies related to Web archiving programs. The responses from this survey document the current state of U.S. Web archiving initiatives and the comparison with the results of the 2011, 2013, and 2016 surveys enables an analysis of emerging trends. This report describes the current state of the field, tracks the evolution of the field over the last few years, and points to future opportunities and developments.