Homeland DefenseSeveral federal agencies are involved in our nation's homeland defense including the United States Coast Guard and the U.S. Immigration and Customs Enforcement. These agencies are both housed within the U.S. Department of Homeland Security. Together these agencies employ more than 21,000 employees in our nation and around the world. Positions span professional, administrative support, technical and trade positions. Local and state law enforcement agencies support the work of these professionals.