Key Concept 9.1 — A newly ascendant conservative movement achieved several political and policy goals during the 1980s and continued to strongly influence public discourse in the following decades.

Key Concept 9.2 — Moving into the 21st century, the nation experienced significant technological, economic, and demographic changes.

Key Concept 9.3 — The end of the Cold War and new challenges to U.S. leadership forced the nation to redefine its foreign policy and role in the world.