I tried to provide original captains pre Prairie Grove. That is when the regiment was reorganized (after PG). Hope this helps some.
Co A. formerly Co H. CPT Pleasant Roper, all enlisted at Trenton not sure which eastern county .
Co B. Looks to be combo of Yell County and Perry County men. Organized from consolidation of old Company F Perry Co. (CPT J. H. Boring) and G Yell Co. (CPT Felix Strayhorn) in December 1862 with Boring as CPT.
Co. C. Looks like Monroe County but could be from another county as well. Co C Monroe Co (CPT J. W. Scaife) consolidation with old Co I. (CPT George Washington) Dec 1862. Both released at consolidtion and CPT Richard Davis (from Jackson Co.) of new company.
Co. D. Saline County. CPT Walton Watkins, son of Judge George Watkins of Little Rock.
Co E. Consolidation of Co E and Co L. Dec 1862. Combo (Co E, Monroe Co. CPT W.J.F. Jones) and Greene Co. (Co L, CPT Joel C. Anderson). CPT Jones commanded after consolidation.
Co F. Yell County. Redesignated from old Co K. CPT George Harrod.
Co G. Madison County. CPT Elbert Dawson.
Co H. Consolidated companies of Perkins and Hailey's cavalry companies (formerly Gipson's BN Mounted Rifles) Hailey's Co from Marion Co and Perkins from Sebastian Co. CPT Hailey commanding.
Co I. Hot Spring County. CPT John B. Torbett KIA Prairie Grove.
Co K. Scott County, Tomlinson's cavalry CPT Wiley A. Tomlinson died of wounds Prairie Grove