Data for Exploration Make Your Own Dataset with Library APIs

Make Your Own Dataset with Library APIs

Can't find a particular dataset you are looking for? The Library provides a number of Application Programming Interfaces (APIs) for users with more advanced technical skills to query, search, and download Library content files and structured data.

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  Loc.gov JSON API The loc.gov API provides structured data about Library of Congress collections. The API was originally designed to power the loc.gov website, but in addition to providing HTML for the website it can provide a wealth of information in JSON format.

  Official documentation	https://www.loc.gov/apis/json-and-yaml/
  Resources	Accessing images for image analysis on Loc.gov (Jupyter Notebook) Using the Loc.gov JSON to grab WWI Sheet Music (Jupyter Notebook) Extracting location data from the loc.gov API for geovisualization with the Historic American Engineering Record (Jupyter Notebook) Color clusters in images in Library of Congress collections (Jupyter Notebook)

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  Congress.gov API The Congress.gov API provides a method for Congress and the public to view, retrieve, and re-use machine-readable data from collections available on Congress.gov.

  Official documentation	https://api.congress.gov/
  Resources	Congress.gov API Github Repository API Endpoint Documentation (Documentation) Congress.gov Java and Python sample client code (Sample code) Introducing the Congress.gov API (Blog post, 2022-09-06)

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  Chronicling America API The Chronicling America API provides access to information about over 12 million (and growing) digitized historic newspaper pages from almost every U.S. state and territory.

  Official documentation	https://chroniclingamerica.loc.gov/about/api/
  Resources	Chronicling America API Guide (Jupyter Notebook) New Interactive Map and Timeline Added to Chronicling America (Blog post, 2022-07-19) Visualizing Chronicling America Data: 15 million pages of digitized historical newspapers (Blog post, 2019-05-21) Chronicling America Maps and Visualizations (Visualization)

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  American Archive of Public Broadcasting (AAPB) API The AAPB Experimental API provides access to information about tens of thousands of historic programs of publicly funded radio and television across America.

  Official documentation	https://github.com/WGBH-MLA/AAPB2#api
  Resources	Experiments with the AAPB API (Exploration)
  Notes	Scholars may request access to JSON and text transcripts for items in the AAPB's Online Reading Room through the AAPB Transcripts Research Access service. Credentials are required to access the transcripts API and can be obtained by contacting [email protected]. Contact AAPB for more information about accessing the collection for digital humanities/research projects.

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  Image Services API The Library of Congress Image Services API specifies a web service that returns an image, or informaion about an image, in response to a standard HTTPS request. The request can specify the region, size, rotation, quality characteristics and format of the returned image or request basic technical information about an image. The API is implemented using the International Image Interoperability Framework (IIIF) Image API.

  Official documentation	https://www.loc.gov/apis/micro-services/image-services/
  Resources	Change image URLs to rotate and resize images on loc.gov (Jupyter Notebook) IIIF at the Library of Congress (Blog post, 2018-05-03) IIIF Image API Documentation (Documentation)

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  Linked Data Service The Linked Data Service provides interactive and machine access to the Library's authority and bibliographic metadata, along with commonly-found standards and vocabularies used and/or maintained by the Library of Congress.

  Official documentation	https://id.loc.gov/
  Resources	Linked Data Service Technical Center Integrating Wikidata at the Library of Congress (Blog post, 2019-05-22)
  Notes	Each controlled vocabulary list has a resolvable URI, as does each data value within it. Ontologies for several major data element sets are also available. URIs accessible at id.loc.gov link to bibliographic descriptions and controlled vocabularies and the values within them. This data service does not provide access to the physical or electronic holdings of the Library.

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  National Library Service (NLS) Bard API The Bard Public API allows searches to be performed against the metadata for the entire BARD collection of the National Library Service for the Blind and Print Disabled.

  Official documentation	https://api.nlsbard.loc.gov/
  Notes	It does not currently allow searches to be performed against the text inside an item. Use of the API does not require password authentication.

• Prints and Photographs Online Catalog (PPOC) JSON API The PPOC API enables access to the content in the Library of Congress's Prints and Photographs Online Catalog, a website focused on the Library's collection of still pictures, including photographs, fine and popular prints and drawings, posters, and architectural and engineering drawings.

  Official documentation	https://www.loc.gov/pictures/api
  Notes	Most of the content in PPOC is also accessible via the loc.gov APIs.

• Search/Retrieval via URL The Search/Retrieval via URL (SRU) servers provide access to Library data, including the catalog and some authority files, via SRU, a standard XML-based protocol for search queries which utilizes the Contextual Query Language (CQL), a standard syntax for representing queries.

  Official documentation	https://www.loc.gov/standards/sru/resources/lcServers.html
  Resources	SRU is Simple! (Guide)

• Streaming Services API Streaming Services is an audio and video (A/V) delivery API based largely on the IIIF Image 2 API which image services implements. In a similar manner, A/V files are accessible by a URI that specifies the region, size, rotation, temporal region, quality characteristics and format of the requested file.

  Official documentation	https://www.loc.gov/apis/micro-services/streaming-services/
  Resources	IIIF Image API 2.0 Documentation (Documentation)
  Notes	A URI can also be constructed to request basic technical information about the resource to support client applications. This API was conceived of to facilitate systematic reuse of AV resources in digital AV repositories maintained by cultural heritage organizations. It could be adopted by any AV repository or service, and can be used to retrieve static AV in response to a properly constructed URI.

• Text Services API The text-services API provides access to the full text, word coordinates and context snippets for certain image based sets of content on loc.gov. These content sets include but not limited to newspapers and selected digitized books.

  Official documentation	https://www.loc.gov/apis/micro-services/text-services/