Henry Louis Gates Jr. talks about artifacts like the afro comb found near the Nile Valley from early African civilizations.

Researchers at Caltech are scaling structures down to the nanoscale in order to make lightweight but strong material.

President John Kennedy deals with communist expansion in Vietnam and promises aid to the South Vietnamese but doesn't plan on large scale involvement of US forces.

Neil deBuck Weasel and the opossums are happy to find space rocks, which consist of iron, carbon, and a hint of nickel. They soon learn that the rocks have unusually strong magnetic fields and attract to each other. Although largely exaggerated, this clip could be used to illustrate magnetism and the elements found on asteroids.

Upton Sinclair's "The Jungle" was intended to be an indictment against unfair labor practices. However, it made an even bigger impact in food safety reforms.