These sources will help you locate entire papers by geographic area and, in some cases, by time period or political stance.
Some may be in the collections at the University Libraries; others may need to be borrowed on Interlibrary Loan (ILLiad).
Need help finding articles on a topic? Look at Newspaper Indexes, instead.
There are a number of specialized guides idenitifying newspapers published for particular audiences, from a particular place, or during a particular time. Here are a few to check for in-depth research:
Arkansas Union List of NewspapersChronological Tables of American Newspapers by History and bibliography of American newspapers, 1690-1820 by 
African-American Newspapers and Periodicals by Black Arkansas Newspapers, 1869-1975 : A Checklist by 
American Indian and Alaska Native Newspapers and Periodicals, 1826-1924 by 
Native American Periodicals and Newspapers, 1828-1982 by 
Hispanic Periodicals in the United States, Origins to 1960 by "Ayers" also known as Rowell's, Directory of Publications, Gale Directory of Publications, etc. is an annual publication listing newspapers and, later in its publication history, radio and television stations, by state and city. Most entries will provide information on editors, circulation figures, ad rates, and publication frequency.
The University Libraries own a fairly solid run of Ayers in microfilm and print. See the chronological list below for holdings.
Rowell's American Newspaper Directory, 1869-1908
[Not held by the University Libraries]
Some years available at the Library of Congress
N.W. Ayer & Son's American newspaper annual, 1880 - 1909
Library Annex Cabinets Z6951 .A97
Some years available on HathiTrust
N. W. Ayer & Son's American newspaper annual and directory, 1910-1929
Library Annex Cabinets Z6951 .A97
Some years available on Hathitrust
N.W. Ayer & Son's directory of newspapers and periodicals, 1930-1969
Library Annex Cabinets Z6951 .A97
Ayer directory, newspapers, magazines, and trade publications, 1970-1971
Library Annex Cabinets Z6951 .A97
Ayer directory of publications, 1972-1982
Library Annex Z6951 .A97 (1972 in PER- MFILM)
The IMS ... Ayer directory of publications, 1983-1985
Library Annex E Z6951 .A97
IMS directory of publications, 1986
[Not held by the University Libraries]
Gale directory of publications, 1987-1989
Library Annex Z6951 .A97
Gale directory of publications and broadcast media, 1990-
Main Z6951 .A97, 2010 - [Latest at Mullins Help Desk]
Library Annex Cabinets Z6951 .A97, 1990-2009
