May 1 US Quarantine Station opens on Angel Island, San Francisco Bay May 11 18th Kentucky Derby: Lonnie Clayton aboard Azra wins in 2:41½ May 19 Charles Brady King invents pneumatic hammer May 19 National Society of Colonial Dames of America founded May 20 George Sampson patents clothes dryer May 21 Ruggero Leoncavallo's opera "I Pagliacci" premieres in Milan May 22 Dr Washington Sheffield invents the toothpaste tube Historic Event May 28 Sierra Club formed by John Muir and others in San Francisco, for conservation of nature Environmental Philosopher John Muir 1891 Historical Events by Year 1893
