Online full-text access to Arkansas Newspapers over time is limited. Most research need to be done using the microfilm of each paper. The library has the film for the following papers and years:
The Arkansas Gazette (1865-1991)
The Arkansas Democrat (1898-1991)
The Arkansas Democrat-Gazette (1991-2018)
Indexing of the newspapers before 1984 is limited. The Arkansas Gazette has a paper index in the reference collection (Call Number: REF AI 21) from 1819 to 1894 and from 1960 to 1991. For the missing decades you have to guess at dates and read the newspaper, or if the event was at a national level, look for the dates of coverage in The New York Times and start with that date in the Arkansas paper.
The Arkansas Democrat does not have an index. It is best to use the same dates found in the index to The Arkansas Gazette and check the day before and day after if you do not find the topic on the same date.