Why, in this day and age, is the US military organized along a structure (Army, Navy/Marines) based on the Elizabethan English military organization (I recognize the USAF was spilt off to avoid a battle between Army and Navy)? For that matter why are dress uniforms based on obsolete English gentlemen's dress? A bit of rethink based on objective/mission seems well overdue. The 1940s reorganization that lead to the Dep…
The USAF was actually split off largely due to the efforts of the bomber mafia to promulgate strategic bombing as a useful method of war. The problem is that strategic bombing doesn't work, and never has, which kind of blunts the purpose of the USAF except as providing largely tactical support for the Army and Marines (note that the Navy runs their own carrier planes, and the Army and Marines also have their own close air support wings).
It's also disingenuous to suggest that the US military is largely based on Elizabethan military terms. The entire concept of the staff system only dates back to roughly Napoleonic Wars (and is most associated with the effective Prussian military). But even beyond that, the US military is largely organized in operational terms under unified (cross-service) commands based on geographical theater, a system that originates in WWII and is pretty much unique to the US (although, to be fair, it's the only country that has the need to work under such a system; however, similar concepts like the Joint Chiefs of Staff don't seem to be particularly widespread in the world).