Statistics for occurrence #1 of “U. S. A.” in chapter 10 of A Roster of General Officers , Heads of Departments, Senators, Representatives , Military Organizations, &c., &c., in Confederate Service during the War between the States.:
...ry U. S. A. with the rank of Brevet Brigadier-General.
General Robert E. Lee was Colonel of the First cavalry U. S. A.
General G. T. Beauregard was Captain and Brevet Major Corps of Engineers U. S. A.
See Official Army Register for September, 1861, page 61
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