Founded in 1853 as A. A. Rosenberg, it was sold to Leander Sherman and Clement Clay in 1870 and was incorporated as Sherman, Clay & Company in 1892. This was a musical instrument retailer and distributor who started in San Francisco and quickly branched out across the western states, and though primarily and piano distributor, they were very influential in the introduction of Ukuleles to the Mainland. 

In 1915 they claimed to be the biggest purveyor of Ukuleles in the world, having sold more than 7000 in their shops in 1914. 

In 1916 Sherman Clay signed an exclusive mainland distribution deal with Jonah Kumalae and they also distributed other Hawaiian makers Ukuleles, (the Hawaiian Ukulele Mfg Co. certainly made instruments for them), They claimed to take the output from two Hawaiian factories but this still wasn't enough and they got local California luthiers to make Ukuleles for them too. All of which usually had a Sherman Clay & Co. label inside the sound home. Sherman Clay also got in on the publishing of Ukulele books at this time too over the next few years they remained a big force in West Coast Ukulele distribution and a major link from the mainland to Hawaii. Though I haven't found the definitive proof, I am fairly sure that Columbia was a Sherman Clay house brand. I know that Columbia Ukuleles came from California, (not Hawaii or a Regal re-brand), I know the range included Guitars, Mandolins and Banjos as well as Ukuleles and I can find no records of anyone but Sherman Clay selling them? They finally stopped selling musical instruments in 2013.