After the September 11, 2001, terrorist attacks in the United States, State officials are playing an increasingly significant role in homeland security. The foundation for this guide is the homeland security priorities identified by State homeland security coordinators. The first section enumerates a definition of homeland security that views homeland security as “a concerted national effort to prevent terrorist attacks within the United States, reduce America’s vulnerability to terrorism, and minimize the damage and recover from attacks that do occur.” The second section assesses how States are assessing homeland security preparedness. A March-April 2002 survey revealed that the most prevalent priorities of States in their security preparedness include first responders, public health, infrastructure security, intelligence gathering and investigation, border security, driver’s licenses and identification cards, mutual aid networks, volunteers and donations, and public notification. State homeland security preparedness has placed an enormous strain on already tapped State and local budgets. Responsibilities that formerly rested with the Federal Government are now suddenly falling under State guidance, which is also producing problems with manpower, in addition to budget considerations. The third section identifies State trends in the areas of organizations structure changes, legislation, and cooperation with the private sector. Following the September 11th terrorist attacks, many States either created new organizational structures for the purpose of preparing for future attacks or they incorporated additional security responsibilities into existing agencies or department structures. The terrorist attacks also spurred a variety of State legislation that addresses homeland security issues, including topics that criminalize acts of terrorism and strengthen emergency health responses. Finally, the private sector plays a critical role in safeguarding America’s citizens and critical infrastructure. Thus, a coordinated plan between State and local governments and private sector businesses is necessary. Overwhelmingly, evidence indicates that the key factor to homeland security rests in the increased cooperation and coordination between all levels of government and private sector businesses. Sharing information about threats and actual attacks increases the likelihood of preventing attacks and swiftly responding to attacks that do occur. Appendices provide glossary terms, identify the primary initiatives of the national strategy, and present examples of State legislation. Tables