Socrata
HTTPS CORS OAuth
Access to Open Data from Governments, Non-profits and NGOs around the world
API Endpoint
https://dev.socrata.com/More Open Data APIs
Unofficial US Federal Government API Development
HTTP CORS ? Free
Normalized historical records and 25 daily-updated reference series
HTTPS CORS Free
Land suitability scoring API for any US property: off-grid, rural, recreational, investment
HTTPS CORS ? apiKey