What is the paraphrased meaning of the quote "Uncommon valor was a common virtue"?

The statement "Uncommon valor was a common virtue" implies that extraordinary courage is a typical characteristic among members of the U.S. Marine Corps. This perspective underscores the notion that, while acts of bravery may be rare in broader contexts, they are often demonstrated routinely by Marines in their duty. This reflects the spirit of the Marine Corps, where high levels of bravery are not just encouraged but are seen as a fundamental aspect of their identity as service members. Therefore, the answer accurately captures the essence of that quote by highlighting the high levels of bravery that are inherent among Marines.