I recently became involved in a discussion/debate regarding whether or not George Washington is senior to John J. Pershing. To me, it seems clear that the resolution of Congress in 1976 (Public Law 94-479) expresses an intention that no one, past or present, ever outrank Washington. However, does this mean that his rank is superior to Pershing's, or merely equal (and, therefore, not techincally outranked)?
It seems to me that date of commission does not apply here.
This recently was answered and the answer is that by law no general will ever outrank GW. He was elevated to a six star General post humously around 1976.