William Larue Weller was born into a distilling family in Kentucky in 1825, and launched his W.L. Weller brand in 1849. Originally a rectification business (creating 'whiskey' using neutral spirit, colouring and flavourings), this all changed with the Bottled in Bond Act of 1897 and the death of Weller two years later. The company was left in the hands of the fiercely passionate Julian 'Pappy' Van Winkle I who, having steered it safely through the wreckage of National Prohibition, established Old Weller alongside the newly acquired Old Fitzgerald labels and the flagship brands for the new Stitzel-Weller distillery in 1933. It was produced there for over 60 years, eventually being sold to the Sazerac Company in 1999, who distil it at Buffalo Trace using Pappy's recipe to this day.

This Buffalo Trace release is from prior to the 2016 rebrand of the range, which saw the "W.L." prefix dropped from the packaging. In her book But Always Fine Bourbon, Sally Van Winkle Campbell claims that Sazerac did not have the exact Weller recipe until their partnership with her brother, Julian Van Winkle III was agreed in 2002. Undoubtedly a nod of approval from the family for the modern day product.

A historic distillery, Buffalo Trace was built in 1812 Harrison Blanton. It was then purchased by the legendary Edmund Haynes Taylor Jr in 1870, who named it OFC (Old Fashioned Copper) and invested heavily in its modernisation. So much so in fact that he declared himself bankrupt after just seven years, and George T. Stagg stepped in to rescue it, becoming its owner in 1878. He ran the distillery until his retirement in the 1890s, and it was renamed in his honour in 1904. Having survived Prohibition, it was bought up by the Schenley company in 1933, who ran it as part of their extensive portfolio for the next fifty years, eventually selling it to Age International. The latter's new Japanese ownership in 1992 had no interest in it (only in its brands), and immediately sold it to the Sazerac company, who renamed it Buffalo Trace in 1999.

In 2016, W. L. Weller 12YO was repackaged in a taller and slimmer bottle.  This is the pre-2016 bottling.