GET /search/
loc.gov:library-of-congress-apis
Summary: Search Collections
Operation ID: searchCollections
Auth: none
Operation ID: searchCollections
Auth: none
Description
Search the Library of Congress collections with optional JSON output format.
Parameters (5)
c
(integer, query, optional)
Number of results per page
fa
(string, query, optional)
Facet filter (e.g., original-format:book)
fo
(string, query, optional)
Output format (json or yaml)
Constraints: {'enum': ['json', 'yaml']}
q
(string, query, optional)
Search query string
sp
(integer, query, optional)
Start page for pagination
Examples (3)
| Title | Type | URL | Action |
|---|---|---|---|
| Search Library of Congress collections | openapi-spec |
https://www.loc.gov/search/?q=constitution&fo=json&fa=original-format:book&c=25&sp=1&dates=1900/1950&all=True |
|
| Search Library of Congress collections | openapi-spec |
https://www.loc.gov/search/?q=constitution&fa=original-format:photo |
|
| Search Collections | openapi-spec |
https://www.loc.gov/search/?q=history&fo=json |
Probe History
Status Codes
| Time | Status | Latency | Size |
|---|---|---|---|
| 2026-03-23 10:23:26.979610 | 200 | 2736ms | |
| 2026-03-23 10:15:25.837947 | 403 | 133ms | |
| 2026-03-23 09:17:59.363292 | 200 | 3099ms |
Response Changes
| When | Old | New |
|---|---|---|
| 2026-03-23 10:15:25.837947 | fc958e9023f8 |
549604e450b3 |
| 2026-03-23 10:23:26.979610 | 549604e450b3 |
d2149301bd71 |