This means that the history of the 4th can be followed by reading the very informational "Arkansas Confederates in the Western Theater" by James Willis. It starts as a history of the Ninth Ark. but quickly becomes a history of Reynold's Brigade (of which the 4th was a member).
Our own Bryan Howerton gives this review at Amazon.com:
Although Arkansas committed most of its men and boys to the Confederate cause, and her regiments served in every theater of the Civil War, there has been precious little attention given to the important role they played. James Willis has fixed that with his landmark book, "Arkansas Confederates in the Western Theater."
When the book was published, the reviewer for the Arkansas statewide newspaper complained that it was "too detailed." For the serious Civil War reader, that phrase is music to our ears.
This massive book (nearly 900 pages) was thoroughly researched and meticulously footnoted. Although all of the Arkansas regiments which served in the Army of Tennessee are covered, the vehicle Willis used to carry the narrative is a day-to-day chronicle of the 9th Arkansas Infantry Regiment. As a counterpoint to the "big picture" of campaigns and battles, Willis provides numerous "soldier's eye" vignettes, using excerpts from letters, diaries, journals, and muster roll entries.
The result is a monument to the perseverance and dedication of the Arkansas volunteers.
Included are several appendices which list a complete regimental roster, casualty lists, officer lists, etc. I continually refer back to this book in the course of my own research.
I highly recommend this book.