You mentioned Bushnell's Keg. Just as effective and likely more "revolutionary" in its design and promise for future warfare was his Turtle. The Turtle failed in its mission to sink a British warship, but then his Kegs also failed except to create some consternation and confusion, and provide fodder for some verse. The Keg was no more an inspiration for Civil War torpedoes or modern mines than the Turtle was a direct inspiration for the Hunley or modern nuclear submarines, but the conception and execution of Bushnell's Turtle was the more innovative and bolder design.
In a different light, I may not agree that the Continental soldier was the most important advance in weaponry for the period, but perhaps the Continental Army itself was, or perhaps the Light Infantry were. The Continental Army provided the basis for all future American miltary forces, an initial step, a building block, that not only served as a foundation in a military sense, but provided the basis for the civilian/military relationship. Civilian soldiers who served for a long term and then returned peacefully to civil life, a commander in chief who retired peacefully from his powerful military position to civil life. The first step in a change in the American attitude towards standing armies (for better or worse).
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