These 29 collections document the history of Hawaii and Micronesia from 1834 to the 1990s. "Annexation of Hawai'i," for example, contains thousands of pages of documents concerning the U.S. plan to annex Hawaii, realized in 1898. Materials include the 1,437-page Blount Report of 1894–95, initiated by President Grover Cleveland on the history of relations between the U.S. and Hawaii and the planned annexation; Congressional debates on the Hawaii Organic Act, passed in 1900 to establish a territorial government; and Hawaiian anti-annexation petitions and protest documents from 1897–98.

"Hawaii War Records" presents 880 photographs documenting the impact of World War II on Hawaii and its people. The "Trust Territories of the Pacific Islands" photo archive provides 52,000 photographs on programs in education, health, and political and economic development in the 2,100 islands of Micronesia administered by the U.S. from 1947 to 1994. The website also includes a collection of 16 Hawaiian-language newspapers.

During World War II, the U.S. Government forced more than 100,000 Japanese Americans to leave their homes and businesses, relocating them to internment camps from California to Arkansas. Well-known photographer Ansel Adams documented the lives of Japanese Americans at the Manzanar War Relocation Center in California—from portraits to daily life, including agriculture and leisure.

This site presents 242 original negatives and 209 photographic prints, often displayed together to show Adams's developing and cropping techniques. His 1944 book on Manzanar, Born Free and Equal is also reproduced. Adams donated the collection to the Library of Congress in 1965, writing, "The purpose of my work was to show how these people, suffering under a great injustice . . . had overcome the sense of defeat and dispair [sic] by building for themselves a vital community in an arid (but magnificent) environment."

This private collection presents more than 15,800 rare historical maps with a focus on North and South America. The collection is accessible via several formats. A standard browser (the "directory") is designed for use by the general public. In addition to two browsers and a "collections ticker" requiring Insight software (available for free download), a GIS browser shows detailed overlays of maps and geospatial data for the more serious researcher.

Many of the U.S. maps are from the late 19th and early 20th centuries and are often notable for their craftsmanship. Materials include atlases, globes, books, maritime charts, pocket and wall maps, and children's maps. Users can zoom in to view details. Overlay capabilities make this site valuable for its ability to convey how locations have changed over time.

These 14 exhibitions include more than 600 maps and related documents on aspects of history revealed through the study of maps. The website provides well-integrated essays of up to 8,000 words for each exhibit and some annotated bibliographies.

Exhibits focusing on American history include "Mapping the Republic," on conflicting conceptualizations of the U.S. from 1790 to 1900; "Exodus and Exiles," on Diaspora experiences of Jews and African Americans; "The American Way," a collection of 20th-century road maps and guidebooks; "Carto-Maine-ia," on popular uses of maps; and "Maine Wilderness Transformed," that examines "the creation of a landscape of exploitation."

In addition, "The Cartographic Creation of New England," addresses European exploration and settlement, "The 'Percy Map,'" presents a significant Revolutionary War map; and "John Mitchell's Map" offers insight into diplomatic disputes. These maps are especially valuable for studying exploration and cartography in American history.

This large collection of maps from the 16th century to the present day focuses on Americana and cartographic treasures.

Materials are organized into seven thematic categories—Cities and Towns, Conservation and Environment, Discovery and Exploration, Cultural Landscapes, Military Battles and Campaigns, Transportation and Communication, and General Maps. Sections include five special presentations.

Users may download maps or zoom in to view details. Seventeen specific map collections contained within this larger site that are of particular importance for the study of American history include "Discovery and Exploration," "The American Revolution and Its Era," "Railroad Maps, 1828–1900," "American Colonization Society Collection: Maps of Liberia, 1830–1870," "Panoramic Maps, 1847–1929," "Civil War Maps," and "Mapping the National Parks."

The site presents more than 90 primary source documents on the first use of nuclear weapons and the end of World War II. The documents are organized under eight topics that include background on the atomic project, target definition, debates on alternatives to first use and unconditional surrender, the Japanese search for Soviet mediation, the Trinity Test, the first nuclear strikes, and the problem of radiation poisoning. Additionally, the site's editor has provided commentary on some of the documents pointing out how they have been interpreted and a short introductory essay that explains the historical context of the documents and the questions they raise. A printable version of the briefing book is also available.