It was none other than Frederick Bean (Tex) Avery, the creator of Daffy Duck, Droopy and Mickey Mantle, that prompted the creation of the small U.S. gallon.
Dr Nostrum recalls fondly the free-wheelin' wind up the skirts holiday with Tex and J Edgar Hoover that caused the final parting of the ways with the Mother country. Neither Tex nor J Edgar liked Fred Quimby much, so he never came along.
J Edgar had been in one of his Texan phases, really for the benefit of Tex, who was the ideal man to lap it all up. On one of the lazier afternoon's J Edgar was sauntering around in his 8.32 Gallon Hat, waving it at all and sundry and flashing a bit of leg. Getting no response, Tex felt the need to big J Edgar up and began insisting that he was a bigger man than an 8.3, and that J Edgar was a 10 all the way in his eyes. And any man that's a 10 should be wearing a 10 gallon hat.
Unfortunately the 10 gallon hat was too big for J Edgar and thus the 8.3 was renamed. The measurement system soon followed with J Edgar reasoning that there was a great psychological benefit to all Americans of being able to say that they could fill up anything with more gallons than their European competitors could for the same amount of work.