This section covers the time period from the end of the American Civil War through the election of 1876. Included are sections on the administrations of Andrew Johnson, Ulysses S. Grant, the election of 1876, and the Boss Tweed scandal.

This section covers the history of the American West in the years following the completion of the American Civil War. Sections from the Diversity collection on the Plains Indian and the end of "the Indian threat" are cross-linked. Sources are still being collected for sections on the railroad, cowboys & gunslingers, and the West in film and in children's literature.

At the close of Reconstruction, America entered a phase of economic and population growth and urbanization that writers Mark Twain and Charles Dudley Warner called "the gilded age" because of the greed and political corruption that characterized the era. This section covers the administrations of Rutherford B. Hayes, James A. Garfield, Chester A. Arthur, and Grover Cleveland's first term.

The AHC marks the beginning of the Progressive Era with the publication of How The Other Half Lives (1890) by Jacob Riis. The era lasted into the 1920s and is covered further in the early 1900s section. Presented here are the entire Riis book, and short descriptions of the Benjamin Harrison & the second Cleveland administrations.

Industrialization brought amazing new technologies to America, especially to the urban centers. New inventions dramatically changed how Americans viewed the world. Among the technologies discussed here are photography, sound, film, and electricity.

Although efforts to achieve racial equality in the United States in the Reconstruction era did achieve some temporary gains, these efforts collapsed into the era of Jim Crow discrimination that would last well into the Twentieth Century. This section covers the history of civil rights in America through the Plessy v. Ferguson Supreme Court decision, which legalized racial segregation and includes a section on the Chinese American experience.