Company I of the Ninth (Nichols') was composed mostly of men from Montgomery and Walker Counties. At the time of their enlistment, the men of the Ninth (Nichols') thought they were in the Fifth Regiment, and some men later filed for pensions stating that they were in the Fifth.
A few years ago, I wrote an article on the Ninth (Nichols') which was published in The Herald, the publication of the Montgomery County Genealogical and Historical Society.
I recently posted most of this article on my website, along with a roster of the soldiers of Company I, and am including the link, below. There are biographical sketches linked to some of the men listed in the roster, including the captain, R. F. Oliver.
I'd like to point out that the regiment called the "Ninth Texas Infantry" under General Maxey was an enirely different regiment and was formed later in the war, in the spring of 1862, in North Texas. The Ninth (Nichols'), which was created to build defenses at Galveston, was formed under Galveston merchant and banker E. B. Nichols in the fall of 1861 as a six-month regiment and was disbanded in spring of 1862.
Regarding Corp. Louis Lachonce of the 9th (Nichols'): he was a mail contractor who carried mail between towns; I have a deed relating to his mortgaging his mail horses.
I will be happy to answer questions, if I can.