Scott County, Arkansas was formed 5 November 1833 from Crawford and Pope counties.
The Scott County Clerk may have genealogy records including marriage, probate, and court records, but three of the seven courthouses in this county have burned down and the fire that destroyed the courthouse in 1882 destroyed all the county records up till that time. For county records before 1833 look in Crawford and Pope counties.
Neighboring counties currently include Logan, Montgomery, Polk, Sebastian, Yell counties in Arkansas and LeFlore County in Oklahoma.
There are a couple of histories and related biographies available for Scott County, Arkansas.
The B.O. Gaines History of Scott County, Volume II, by B.O. Gaines, at Google Books
History of Scott County Arkansas, by Henry Grady McCutchen, 1922, at Internet Archive