The Library of Congress Newspaper Directory searches U.S. newspapers published since 1690 by place and date.
If you're trying to identify what newspapers were published in a particular place at a particular time, the Boston Public Library has digitized a number of newspaper directories for various years.
If dates of coverage are included in an entry for a newspaper, the source may or may not include all issues within the listed time period. Dates of coverage were correct when they were entered, but may have changed since then.
A complete list of newspapers available at Google News Archive is at: http://news.google.com/newspapers That list is arranged by title of the newspaper and provides a browsable list of all issues available.
To find the newspaper you want, click on the first letter of the alphabet for the state in which it was published.
Example: To find the Toledo Blade, click on the "O" for Ohio.
To find the newspaper you want, at the top of this page, click on the Alphabet Tab of the first letter of the state in which it was published.
Example: To find the Toledo Blade, click on the "O" for Ohio.