Visitors to this site are invited to explore historical aspects of the roughly 200 National Park Service locations designated important to U.S. history and prehistory. Materials are organized by "cultural resource subjects," including archeology, architecture and engineers, cultural groups, cultural landscapes, historic buildings, mapping, maritime and military history, and "cultural resource programs," such as the American Indian Liaison Program and Heritage Preservation Services.

Visitors can search for information on more than 2.5 million Civil War soldiers and sailors; more than 71,000 properties listed in the National Register of Historic Places; and approximately 240,000 reports on federal archaeological projects in the National Archaeological Database. National Register Travel Itineraries provide historic guides to 18 cities and communities. The National Underground Railroad Network to Freedom contains information on 51 sites of importance and on slavery and antislavery efforts.

Also of interest are bibliographies on the African American west and public history, and full-text publications on the Antiquities Act of 1906 and the promotion of the city of Seattle during the gold rush era. The homepage—"History and Culture"—presents several topical, comprehensive historical exhibits including the "Eisenhower Virtual Museum."

A collection of more than 1,100 topographical maps created by the United States Geological Survey from the 1890s to the 1950s covering all of New England—Maine, New Hampshire, Vermont, Rhode Island, Massachusetts, and Connecticut—and selected areas of New York. The maps—which reveal roads, buildings, rail lines, bodies of water, and elevations—occur in 15-minute and 7.5-minute quadrangle series (a minute is one-sixtieth of a degree of latitude or longitude). In addition, the collection includes six maps with 30-minute quadrangles.

For states other than New York, users can view a state image map and select a point within a grid marked off in 15-minute increments to find listings for available images accompanied by dates the maps were surveyed, created, and revised. Towns within each quadrangle are also listed along with names of adjacent areas. Users also may search an alphabetical list of towns within each state. For New York, only an index of quadrangles names is available. Maps are presented in JPEG format. According to the site, "Each image is typically 2 megabytes, so download times are likely to be slow." A useful site for those studying changes in the New England landscape during the first half of the 20th century.

This 1995 exhibition presents approximately 70 maps designed to help "understand [Thomas] Jefferson's views of the West and the nature of the quest to the Pacific," and to "show the evolution of cartographic knowledge of North America up to the time that [Meriwether] Lewis and [William] Clark set out."

Arranged into five sections, it treats the period from the arrival of Columbus in North America to Lewis and Clark's 1803 voyage.

Well-written background essays describe relevant monographs and journals, explain the role of technology in mapmaking, and elucidate the social and intellectual contexts of Western exploration.

The site, which offers both European and American perspectives, also furnishes eight related links and a 31-title bibliography.

Particularly useful for understanding the evolution of geographic knowledge about North America and for tracing the history of cartography during this period.

By the time Thomas Jefferson became the third President of the United States in 1801, interest in exploring the West had begun to shape U.S. policy. This chronological narrative traces Jefferson's life, participation in politics, and accumulation of scientific geographical knowledge from 1735 to 1804. There are four main sections: "The Jeffersons and Their Frontier Virginia Neighborhood," "From Colony to Commonwealth," "Science and Statecraft at Home and Abroad," and "Public Servant to the Early Republic."

This narrative is accompanied by an archive of 169 letters, statues, books, treaties, maps, and journals providing primary source insight into Jefferson's thoughts about the West and the Lewis and Clark expedition in particular. Three interactive maps from the 1700s, overlaid with historical data about cities, private dwellings, natural features, courthouses, and waterways, provide important insight into the geographic and social environment at the time.

Provides historical United States Geological Survey maps of the San Francisco Bay area, from Point Reyes in the north to Half Moon Bay, and east to San Jose. Includes maps from different time periods—the earliest is from 1895, the latest 1997—covering each 7.5-minute and 15-minute quadrangle of the area. Users may zoom in to see minute details. Searchable by quadrangle or place name. Of value for those studying change over time in the development of the Bay Area during the 20th century.

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."

In 1912, Japan presented Washington, DC, with 3,000 cherry trees as a gift. This Library of Congress exhibit uses primary sources to explore the history of the trees, the National Cherry Blossom Festival that grew up around them, and Japan/U.S. relations.

Primary sources are divided up by four themes. "Art and Documentation" includes three sources: a letter from Tokyo mayor Yei Theodora Ozaki to First Lady Helen Taft on the gift of the trees, a memo on artwork acquired by botanist Walter Tennyson Swingle in Japan, and a photograph of Swingle and Seisaku Funatsu, one of the group of Japanese experts who cultivated the trees gifted to the U.S.

In "A Special Gift to Washington from the City of Tokyo," visitors can view Swingle's collection of 11 Japanese watercolors depicting different types of cherry trees.

"Cherry Blossoms in Japanese Cultural History" collects 15 pieces of Japanese artwork depicting traditional hanami (flower viewing), as well as two pieces of Western artwork showing Japanese influence. Also included in this section are 12 stereographs of Japan during cherry blossom time, created between 1904 and 1908 for Western audiences.

"Enduring Symbols of Friendship" includes nine sources exploring the place of the cherry trees in Japan/U.S. relations. A 1938 Japanese magazine cover, notes for a 1934 speech by Japanese ambassador Hiroshi Satou, and a photo of children from the Japanese Embassy at the Tidal Basin show pre-World War II peace. Two political cartoons show how quickly the trees became a symbol of DC, and a photograph shows U.S. cherry blossom viewers during World War II. The section also features three photographs from a 2011 photography contest associated with the National Cherry Blossom Festival.

Visitors can also click on "Exhibition Items" to view all 55 primary sources, sortable alphabetically or by theme.

Some sources lack annotations, and existing annotations are sparse. However, this is a unique collection of sources that could be used as jumping-off points for exploring cultural exchange, international relations over time, and DC history.