Although the preparation of pisco-based mixed beverages possibly dates back to the 1700s, historians and drink experts agree that the cocktail as it is known today was invented in the early 1920s in Lima, the capital of Peru, by the American bartender Victor Vaughen Morris. Morris left the United States in 1903 to work in Cerro de Pasco, a city in central Peru. In 1916, he opened Morris' Bar in Lima, and his saloon quickly became a popular spot for the Peruvian upper class and English-speaking foreigners. The pisco sour underwent several changes until Mario Bruiget, a Peruvian bartender working at Morris' Bar, created the modern Peruvian recipe of the cocktail in the latter part of the 1920s by adding Angostura bitters and egg whites to the mix.