The Interactive Constitution (National Constitution Center)

Free lesson plans, primary sources, and virtual field trips from national parks and historic sites, covering history, science, and civics. Includes the Teaching with Historic Places series.

Free map quizzes for learning countries, capitals, states, flags, and landmarks around the world, with many difficulty levels. Quick geography practice for any grade.

Free 3D globe and mapping tool for virtual field trips, geography, and environmental studies, with guided stories and tools for creating custom projects.

Nonprofit, free reference with articles, timelines, maps, and images covering world history from prehistory onward. A good starting point for student research.