I can not add much to George's comments, but some conjecture. Sergeant Beckett was on the Holy Springs Raid on 19 Dec 1862. He was with the unit at The Battle of Thompkin's Station TN and was probably promoted to Lieutenant due to a growing shortage of officers. During the remainder of 1863 and early 1864 the 9th was in north and west Mississippi. For detail on George Grissom's Diary. He was an adjutant of the 9th and wrote daily of the unit. This is an old book but is still available in some libraries. April and May 1864 the Unit moved east across Mississippi and Alabama, and arrived in the Rome GA area about the 15 of May 1862. For the next 100 days of the Atlanta Campaign, the unit part of Ross' Brigade was whittled down from about 3000 to 1000. About the time of the fall of Atlanta, the Regiments were down to 200 and officers were given the choice of fighting as enlisted or in a company of Officers operating as a Ranging and Reconnacense Company commanded by a captain from the 6th Texas. Most of the excess Captains chose the latter. Whether Captain Beckett chose this route is not known. It was a wild aggressive company, and is known to have charged and routed a regiment. Not much else is known or has been written or found.

I would check Grayson County before and after the war, especially the census. His failure to be on a list of officers paroled at the end of the war was an indicator he was probably in the officer company and was back in Texas recruiting with Sul Ross. With the news of the wars end, they just milted into the population.

Some of this is just conjecture, as only a few of the officers of this company are known. A Naval Major is writing a book about the Commander of the Officer Company and may have come up with something. The book, Fighting With Ross' Texas Cavalry Brigade, the Diary of LT George L. Griscom, Adjutant of the 9th Texas Cavalry Regiment, edited by Homer L. Kerr, Hill Jr College Press, 1976 gives life to the 9th Texas Cavalry. A Thousand Texans, Men of the 9th Texas Cavalry describes many of the men and stories of the 9th, but adds nothing to J. W. Beckett. This book was written by Stephen Kirk a couple of years ago. Google Kirk. Feel free to view as much as I have put on line to date. I have been waiting for Kirk to put out his book on Ross' Brigade. I just hope his health has held up.