This is (about) what I repleid earlier, that was blocked by accident:
John Tyner Loudon was born in Williamson County, IL in 1821, died in/near Fort Smith in March 1866. He married Mary Inge, doubtless a relative of the Captain Inge who commanded a company in this battalion. He was Williamson County clerk in the 1840s and a delegate to the IL Constitutional Convention of 1847. To Fort Smith c. 1859, and practiced law there. A Unionist in 1860. After his CSA service, he enlisted in the 3rd AR Union Infantry in Dec. 1863, rising to captain and judge advocate. His daughter Lula (Graham) got a Union army pension for his service, and perhaps her pension app contains more on Loudon's CW service.