The unit referred to was, as logic dictates, a U.S. post-Civil War unit. Not quite sure what the relevance of the Missouri Army Argus was all about, but the Brookfield Argus was first published in 1882, and was still going strong at the time Company A, 6th Missouri Volunteer Infantry mustered in at Brookfield on July 20, 1898.
Commanding officer was John H. Goldman, Brookfield. Other officers and non-commissioned officers were 1st Lt. Downey Milbourne, Linneus, Mo; 2nd Lt. Henry J. West, Marceline; 1st Sgt. John W. Wrenn, Marceline; Quartermaster Sgt. David F. Fawks, Marceline; Sgt. Ephraim P. Banning, Brookfield; Sgt. Thomas A. Scott, Rothville; Sgt. William D. Brown, Laclede; Sgt Benjamin E. Bowyer, Linneus; Cpl. Charles W. Wright, Brookfield; Cpl. William T. Lamme, Laclede; Cpl. George P. Fawks, Carrollton; Cpl. William Olinger, Marceline; Cpl. Robert O'Donnell, Carrolltown; Cpl. David S. Bramhall, Unionville; Cpl. Charles E. Crumley, Marceline; Cpl. William Trippler, Linneus; Cpl. Jasper Knight, Linneus; Cpl. William Hoar, Brookfield; Cpl. Samuel H. King, Brookfield; Artificer John A. Conners, Brookfield; Wagoner Henry Coleman, Hazelhurst Mississippi; Musician Guy M. Kerr, Brookfield; Musician Charles E. Plummer, Milan.