Explore walking upright, tools and food, bodies, brains, social life, language and how humans ultimately changed the world. Excellent charts, pictures and videos accompany easy-to-understand text on the earliest humans.

The study resource from Khan Academy provides an overview of Period 6: 1865-1898 in American History. Reform in the Gilded Age is discussed in this lesson. This resource is designed as a review for the AP US History Test.

Comparing and contrasting are skills that are utilized in this lesson plan. Teacher resources and detailed activities will help the students learn about the schools in early America.

This Khan Academy resource provides historical information about the annexation of Texas.

Through primary source documents, discover the history of NASA's "human computers," early aerospace industry pioneers, and the struggle for American women to be allowed into the astronaut program.