Jacob S. Davis enlisted in Co. E, 14th (Power's) Arkansas Infantry, at Yellville, Arkansas, July 17, 1861, for twelve months, and was elected first lieutenant. When the regiment was reorganized at Camp Churchill Clark, near Corinth, Mississippi, on May 8, 1862, he did not stand for reelection (perhaps due to his injury); so he was discharged on May 23, and dropped from the rolls on June 30, 1862.
I can't find any record of subsequent service in any other Arkansas regiment.
He applied for a Confederate pension from Madison County in 1906 (Pension File No. 10430).