2003 Homeland Security Presidential Directive (HSPD)-5, Management of Domestic Incidents- directs the Secretary of Homeland Security to develop and administer a National Incident Management System (NIMS) and improve coordination in response to incidents.

 http://www.dhs.gov/publication/homeland-security-presidential-directive-5

2011 Presidential Policy Directive (PPD)-8, National Preparedness- companion to HSPD-5 and directs the Secretary of Homeland Security to require a national domestic all-hazards preparedness goal, establish mechanisms for improved delivery of Federal preparedness.

http://www.dhs.gov/presidential-policy-directive-8-national-preparedness

2016 Presidential Policy Directive (PPD)-44, Enhancing Domestic Incident Response. 

PPD-44 Domestic Incident Response_110816.pdf 

The National Response Framework (NRF) Resource Center: http://www.fema.gov/national-response-framework

FEMA National Incident Management System (NIMS): http://www.fema.gov/national-incident-management-system

The Incident Command System (ICS) Resource Center: ICS Resource Center (fema.gov)

 Disaster declarations: Disasters and Other Declarations | FEMA.gov