Yupper,
A bucket was the best way to carry brew from 'A' to 'B' back then. Since local water was not necessarily the best thing to drink, local brews were. Many Saloons that had their own brewery had young boys willing to make a few bucks daily to carry a bucket down the street to a buyer, this is a given in the Old West.
If any of you Pards recall, the bucket of beer was seen in the Kevin Kostner version of TOMBSTONE, the Earp brothers are all in Tombstone, setting outside back of Wyatt's house in a sorta porch with a table, inside a vertical stick wall and a young boy shows up with a bucket of brew which they all dip a cup into.
This concept has been used at many new venues to carry on the historical tradition and offer an different way to enjoy the beverage, to wit, the Iowa State Fair where a wood building looking like an Old West Saloon serves steaks and suchlike and brew in an aluminum bucket which you can keep, if you so desire, or at least that was the way they did it the last time I was there a few years back. They also offer a Hot Beef Sundae, mashed 'taters with shredded hot beef and gravy then covered with shredded cheese and topped with a Cherry 'mater, yummy!
Best regards and good eating and don't spill the bucket!
'Ol Gabe