This is a guide to finding sources for NYC-related topics. In addition to the usual places to search, here's some NYC-specific resources. Please add to this is if you know of any more.
New York Public Library edit
https://www.nypl.org/. Anybody can search the general or research catalogs, but you will need a NYPL library card to check out materials. Any NYC resident (13 years or older) can get a card for free. You can request that any circulating material be delivered to your local branch where you can pick it up and return it. Most research material does not circulate and must be viewed at the branch where it is stored. The librarians are extremely helpful with research questions asked via email.
NYC Municipal Archives edit
There's a lot of information in the NYC archives. It's not well organized, but given the depth and breadth of the collection, it's worth the effort to search. Includes a collection of 720,000 photos taking in the 1940s and the 1980s to document every building in the city. The Municipal Archives and Library are is available to researchers by appointment.
- https://www.nyc.gov/site/records/index.page. Tons of stuff, including a treasure trove of historical photos of the city.
- https://nycma.lunaimaging.com/luna/servlet Historical photographs.
Newspapers edit
New York Times edit
https://www.nytimes.com/. In addition to their national and world coverage, the NYT has extensive coverage of local topics, with on-line archives going back to the 1800's. Their archives are an excellent resource for articles about NYC history. Some archival material is available to anybody, some is behind their paywall and requires a NYT subscription to access.
Daily News edit
https://www.nydailynews.com/. Major daily newspaper. Doesn't have the prestige of the NY Times, but still a WP:RSP and a more NYC-centric focus.
New York Post edit
https://nypost.com/. NYC's third big paper, founded in 1801. Once well respected, in the modern era the Post's reputation as a WP:RSP has declined and facts should be corroborated against better sources.
Brooklyn Eagle edit
https://brooklyneagle.com/ current events from Brooklyn since 1996.
https://www.newspapers.com/paper/the-brooklyn-daily-eagle/1890/. Original newspaper now defunct. Archives via newspapers.com for years 1841 to 1955.
Historical societies edit
New York Historical Society edit
https://www.nyhistory.org/. The NYHS archives are indexed via the NYU special collections website (https://specialcollections.library.nyu.edu/search/). Once you have found the material you wish to view, you need to make an appointment to see it in person at the NYHS building (W 77th St and Central Park West). There's no charge for access, but it may take a while to get a research appointment. The trip is worth it just to see the building.
Westchester Historical Society edit
https://westchesterhistory.com/. What is now the Bronx was part of Westchester County until 1873 (Western portion) or 1895 (Eastern portion). Thus, the WHS has significant material in their archives about what's now the Bronx. Extremely useful for researching Bronx historical topics.
Pelham Historical Society edit
http://www.pelhamnhhistory.org/. As with the Westchester Historical Society, lots of good material here on pre-consolidation Bronx history.
Queens Historical Society edit
https://queenshistoricalsociety.org/. Library & Collections only available by appointment. No online catalog.
Museums edit
Museum of the City of New York edit
https://www.mcny.org/. Particularly useful for contemporary material, but also has a deep archive of NYC historical artifacts. Searchable on-line. Unfortunately, their photo reproduction policies don't play well with commons, and their web site states they do not handle research enquiries.
New York Transit Museum edit
https://www.nytransitmuseum.org/exhibits-collections/collections/. Lots of stuff about the history of transit in NYC. They have a research department and allow researchers access to their archives via appointment. Unfortunately, they don't have commons-compatible licensing terms, but still a useful resource.
Photo Archive edit
Urban Archive edit
https://www.urbanarchive.org/cities/nyc collection of public domain images from various GLAM sites. Linked items use Urban Archive ID (P9431) in Wikidata.
Library of Congress edit
https://loc.gov/. There's substantial coverage of NYC topics in their on-line database. Especially valuable is their Chronicling America collection which has extensive holdings of old NYC newspapers, available as digitized page images. As with the NYPL, the LOC librarians provide expert and willing assistance with research questions.