Through its Articles & Databases page, the New York Public Library provides access to numerous electronic resources that contain newspapers and other periodicals. Some are subscription databases available remotely with a library carrd, others are available on site at NYPL branch and/or research libraries, and others are open access resources available anywhere without a login. Searching on the word newspapers turns up more than 160 resources that can be filtered further by subject or availability. Access them here: NYPL Newspaper Resources.