Today in 1876, US Patent 172687 A was issued, an invention of Louis Baeppler, for his “Improvement in Beer-Coolers.” There’s no Abstract, but the description includes this:

My invention relates to an apparatus which maybe readily applied to a keg or barrel of any description, so as to cool the beer after it leaves the barrel.

The invention consists of an ice-chamber, provided with an opening at the bottom for the insertion of a cock to be attached to the lower end of the cooling-coil, and an opentopped slot at the top for the insertion and removal of the upper end of the coil, and a cover for closing said chamber, as hereinafter described and shown.