Capt. Benjamin E. Nicholson of Co. B, Hampton Legion Cavalry, Gary's Brigade, appointed Major September 24, 1864 for valor & skill, to take rank September 3, accepted October 7, wounded at Darby Town road October 13, 1864

His is listed on a Roll of Prisoners of War, as:

B. E. Nicholson, Colonel, Hampton’s S. C. Cav. surrendered at Augusta, Ga. May 23, 1865

Note, there is no other reference in his record as to a rank of Colonel

M267: Compiled Service Records of Confederate Soldiers Who Served in Organizations from the State of South Carolina

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The following must be post-war honorary titles.

Gen Benjamin E. Nicholson
http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRid=92230860

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General B. E. Nicholson, a distinguished Confederate soldier, who was given a vote of thanks by the General Assembly of South Carolina for his gallant conduct at the first battle of Manassas where he captured a Federal flag.

Men of the Time: Sketches of Living Notables. A Biographical Encyclopedia of ... By J. C. Garlingtonp. p. 331
https://books.google.com/books?id=sEQEAAAAYAAJ&pg=PA331&lpg=PA331&dq=Confederate+soldier+Benjamin+E.+Nicholson&source=bl&ots=bwI_b9ny0D&sig=_Z2NUxtO8-ocLVMV9S7UqULxcfk&hl=en&sa=X&ei=KjoHVbmhMILkoATRpILgBQ&ved=0CB4Q6AEwADgK#v=onepage&q=Confederate%20soldier%20Benjamin%20E.%20Nicholson&f=false

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During the fight Lieut. B. E. Nicholson captured a stand of colors. Private Henry Brancies, Company C, also captured a beautiful flag.

2nd Manassas, VA after action report: No. 151.
Report of Lieut. Col. M. W. Gary, Hampton Legion, of the battle of
Manassas.
Source: Official Records
CHAP. XXIV.] CAMPAIGN IN NORTHERN VIRGINIA. PAGE 610-16 [Series I. Vol. 12. Part II, Reports. Serial No. 16.]