Chronicling America vs MarketAux

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.

Marketaux focuses on financial and stock-market news, tagging articles with entities, tickers, and a -1 to +1 sentiment score across over 200,000 entities and 5,000+ sources in 30+ languages. The free plan allows 100 requests/day returning up to 3 articles each; paid Basic through Pro 50K tiers raise both the daily request cap and articles-per-request limit, plus unlock the entity-level Market Stats endpoint. Access is JSON over a single API-key parameter.