Library of Congress APIs

www.loc.gov · Government

Government No Auth Free & Open Government History Culture

Access the Library of Congress digital collections — millions of photographs, manuscripts, maps, newspapers, audio recordings, and more. No API key required.

Authentication

No authentication requiredFree to use with no key needed.

Sample Requests

GET Search collections

Search all Library of Congress digital collections.

https://www.loc.gov/search?q=civil war photographs&fo=json

Hover any highlighted part to learn what it does

curl -X GET "https://www.loc.gov/search?q=civil%20war%20photographs&fo=json"

import requests
params = {
    "q": "civil war photographs",
    "fo": "json"
}
response = requests.get(
    "https://www.loc.gov/search",
    params=params,
)
print(response.json())

const url = new URL('https://www.loc.gov/search');
url.searchParams.set('q', 'civil war photographs');
url.searchParams.set('fo', 'json');

const response = await fetch(url); 
const data = await response.json();
console.log(data);

package main

import (
	"fmt"
	"io"
	"net/http"
	"net/url"
)

func main() {
	baseURL, _ := url.Parse("https://www.loc.gov/search")
	q := baseURL.Query()
	q.Set("q", "civil war photographs")
	q.Set("fo", "json")
	baseURL.RawQuery = q.Encode()
	targetURL := baseURL.String()
	req, _ := http.NewRequest("GET", targetURL, nil)

	client := &http.Client{}
	resp, _ := client.Do(req)
	defer resp.Body.Close()
	body, _ := io.ReadAll(resp.Body)
	fmt.Println(string(body))
}

require "net/http"
require "json"

uri = URI("https://www.loc.gov/search")
uri.query = URI.encode_www_form({
  "q" => "civil war photographs",
  "fo" => "json"
})

http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = uri.scheme == "https"

req = Net::HTTP::Get.new(uri)

res = http.request(req)
puts JSON.parse(res.body)

<?php
$url = "https://www.loc.gov/search?" . http_build_query([
    "q" => "civil war photographs",
    "fo" => "json"
]);
$opts = ["http" => [
    "method" => "GET",
]];
$ctx = stream_context_create($opts);
$res = file_get_contents($url, false, $ctx);
print_r(json_decode($res, true));

GET Search newspapers

Browse the Chronicling America historical newspapers collection.

https://www.loc.gov/collections/chronicling-america?fo=json

Hover any highlighted part to learn what it does

curl -X GET "https://www.loc.gov/collections/chronicling-america?fo=json"

import requests
params = {
    "fo": "json"
}
response = requests.get(
    "https://www.loc.gov/collections/chronicling-america",
    params=params,
)
print(response.json())

const url = new URL('https://www.loc.gov/collections/chronicling-america');
url.searchParams.set('fo', 'json');

const response = await fetch(url); 
const data = await response.json();
console.log(data);

package main

import (
	"fmt"
	"io"
	"net/http"
	"net/url"
)

func main() {
	baseURL, _ := url.Parse("https://www.loc.gov/collections/chronicling-america")
	q := baseURL.Query()
	q.Set("fo", "json")
	baseURL.RawQuery = q.Encode()
	targetURL := baseURL.String()
	req, _ := http.NewRequest("GET", targetURL, nil)

	client := &http.Client{}
	resp, _ := client.Do(req)
	defer resp.Body.Close()
	body, _ := io.ReadAll(resp.Body)
	fmt.Println(string(body))
}

require "net/http"
require "json"

uri = URI("https://www.loc.gov/collections/chronicling-america")
uri.query = URI.encode_www_form({
  "fo" => "json"
})

http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = uri.scheme == "https"

req = Net::HTTP::Get.new(uri)

res = http.request(req)
puts JSON.parse(res.body)

<?php
$url = "https://www.loc.gov/collections/chronicling-america?" . http_build_query([
    "fo" => "json"
]);
$opts = ["http" => [
    "method" => "GET",
]];
$ctx = stream_context_create($opts);
$res = file_get_contents($url, false, $ctx);
print_r(json_decode($res, true));

Postman Setup Guide

Get Postman ↗

No API key needed
Append ?fo=json to any loc.gov URL to get JSON
Try GET https://www.loc.gov/search/?q=apollo+moon+landing&fo=json
Browse collections at https://www.loc.gov/collections/?fo=json
Chronic America newspapers: https://www.loc.gov/collections/chronicling-america/?fo=json

What can you build with Library of Congress APIs?

Library of Congress APIs is a Government API. Developers commonly use government APIs for:

surfacing public datasets in citizen-facing apps
building transparency and civic engagement tools
accessing legislation, court records, and official data
powering research and journalism tools
creating compliance and regulatory monitoring dashboards

No authentication required. This API is open — no signup or key needed. Ideal for quick prototypes and public-facing features. Library of Congress APIs is free to use, making it a low-risk choice to experiment with.

New to APIs? Read our beginner's guide

Open documentation ↗