McNeill served as colonel of the 30th Arkansas Infantry for a time before resigning in November 1862. The following year he was lieutenant colonel of the 19th Louisiana Cavalry Battalion which later became the 4th Louisiana Cavalry. The info you posted regarding the pension is the pension index. You can download a copy of his actual pension record here (there are several pages):
https://familysearch.org/pal:/MM9.3.1/TH-1-16102-42672-35?cc=1837922&wc=6960263

According to it Maxwell served from September 1, 1863 to the end of the war.

I don't see a service record for him.