Physicians Charles H. Mayo (1865–1939) and William J. Mayo (1861–1939) worked together in the family’s medical practice, which eventually evolved into the famed Mayo Clinic in Rochester, Minnesota. Vintage ink signatures, “W. J. Mayo” and “C. H. Mayo,” on an off-white 3.5 x 2.5 card. In fine condition, with mild toning to each corner tip. RRAuction COA.
