History about Speaker: A soldier at the lab, Major Thomas Dennehy, drew up the initial design in thirty days. But he couldn’t solve the problem of a locking mechanism that would keep the blade from opening when not in use.
That final design step fell to John W. Speaker, an immigrant from Austria who had watched from afar as Nazis took over his native land. He had two things making him a good fit for the challenge: a passionate hatred for Hitler and a metal shop in Milwaukee that made automobile parts. He used the latter to perfect a special hinge which kept the blade snapped shut when not in use. The former inspired him to refuse any royalties for his invention. He was a patriot and wanted to do his part to win the war.
JW Speaker Company would go on to manufacture over 50 million P-38s at the cost of about a penny-a-piece.
Speaker didn’t label the device a “P-38.” Rather, it got a typical Army designation: “Opener, Hand, Can, Folding, Type 1.”