Here is what I found on the Illinois Adjutant General Web site: Description: From a tag attached to this flag it reads: "Confederate Artillery Flag. This flag was captured by Newton McCan, a private soldier, Co. M, 2nd Regiment U.S. Regulars, on the evening of July 3rd 1963 at Gettysburg, Pennsylvania. Presented to the State of Illinois on 14 July 1885." The 2nd Regiment of U.S. Cavalry was part of the Cavalry Corps of the Army of the Potomac. According to Confederate records, Moody's Battery or Moody's Artillery was in the battalion of Reserve Artillery on the Confederate right on 2 July, 1863 and may have accidently left their flag on night movement. O.R. Series I, Vol. 27, Pt. 1, pp387-388 and 429-431. civil-war.com/searchpages/confdetail.asp?ID=10
As we know, Yankees 'never' lie.
JIM T