The American pharmaceutical company Merck & Co. was established as a subsidiary of Merck in 1891, but was nationalized by the United States in 1917, before being privatized again when George W. Merck purchased back the stock in 1919.[6] It is known as MSD (Merck Sharp and Dohme) outside of North America. The original Merck of Darmstadt holds the rights to the name Merck in all countries except the U.S. and Canada, where it is known as EMD (Emanuel Merck, Darmstadt). In 2015 Merck adopted a new uniform brand identity for all its subsidiaries, and the company has stressed its intention to protect the brand of "the real Merck" globally and initiated litigation against its former subsidiary over use of the name.[2]