Chronicling America vs The Guardian

Chronicling America is the Library of Congress's searchable archive of historic U.S. newspaper pages published through 1963, built from the National Digital Newspaper Program. As of August 2025 its data moved fully onto the general loc.gov JSON/YAML API, retiring the old chroniclingamerica.loc.gov endpoints in favor of structured search, batch, and full-text access — no API key is required, though heavy use should self-throttle.

The Guardian's Open Platform serves the publication's own articles, tags, and section metadata across more than 1.9 million pieces of content, with a free Developer key limited to 1 call/second and 500 calls/day for non-commercial projects. A separate Commercial key removes those caps for a usage-based fee and adds images, audio, and video. Requests are authenticated with an API key and return JSON by default, with an XML format option available.