US Department of State: A prominent Washington, D.C.-based governmental body, the US Department of State is the lead executive department responsible for the nation’s foreign policy and international relations. Established in 1789, it is the oldest federal department. Its primary mission involves advising the President on global affairs, administering diplomatic missions worldwide, negotiating treaties, and protecting U.S. citizens abroad. The Department focuses on promoting peace, stability, democracy, and U.S. interests through diplomacy, international cooperation, and addressing global challenges like terrorism.