The Star-Spangled Cross and the pure field of white refers to the second national Confederate flag, also known as the Stainless Banner. It was adapted on May 1, 1863, and was the flag under which the Battle of Gettysburg was fought. Because it was predominantly white, it was easily mistaken for a flag of surrender when hanging against a staff. To correct this serious defect, the Confederate Congress authorized a third national flag, which added a broad band of red across the end. It was never actually used, however, since the war ended before it could be produced and issued.

The Stainless Banner

"The Star-Spangled Cross and the Pure Field of White"