The Department of Homeland Security (DHS) was established in 2003. It took on several functions and agencies related to national security, including the Coast Guard, emergency management, border security, immigration, and customs.
Government Documents holds a small collection of DHS publications, but most DHS publications are issued online only or are not publicly available.
We also have Congressional hearings related to homeland security, transportation security, immigration and border protection, and other aspects of DHS's activities, which you can find using OneSearch. Please ask a Government Documents Librarian for assistance.