The Seventh Louisiana Regiment led Colonel Jubal Early’s brigade onto the Manassas battlefield on July 21, 1861, with the 13th Mississippi next in the column and the Seventh Virginia bringing up the rear.

And the story goes that Gen. P.G.T. Buearegard mistook the Seventh Louisiana’s Confederate First National flag for the Stars & Stripes of a flanking Union unit and almost ordered a retreat of his forces, which could have swung the battle to the Union.

Instead, he figured out his confusion in time and the rest is history. Including his decision to create the Saint Anthony’s Andrews Cross battle flag to eliminate future such problems, according to this piece from the Richmond Daily Dispatch of Nov. 27, 1861.

Via Bull Runnings.