Encyclopedias, Almanacs, Transcripts, and Maps
- Interposition
- Interpretivism
- Interrogation: Torture Techniques and Technologies
- Interstate Commerce
- Interstate Commerce Act 24 Stat. 379 (1887)
- Interstate Commerce Commission v. Cincinnati, New Orleans & Texas Pacific Railway 167 U.S. 479 (1897)
- Interstate Commerce Commission v. Illinois Central Railroad 215 U.S. 452 (1910)
- Interstate Compact
- Intrastate Commerce
- Introduction to Expansion to the Mississippi (1801–1861)
- Introduction to the Civil War Era (1850–1877)
- Introduction to the Colonial Era (1585–1763)
- Introduction to the Gilded Age (1870–1900)
- Introduction to the Great Depression and World War II (1929–1945)
- Introduction to the Internet Age (1980–Present)
- Introduction to the Postwar Era (1945–1970)
- Introduction to the Precolonial Era (1450–1620)
- Introduction to the Progressive Era (1890–1930)
- Introduction to the Watergate Era (1968–1979)
- Invalid on its Face