'GAR', or Grand Army of the Republic, I know about, this being a Civil War veteran on the Yankee side, the equivalent of the Confederate cross marking a smattering of graves in old cemeteries back home (like my great-great-grandfather's nr Hope, Arkansas). But 'NSGW' was a new one to me. At first I thought it might relate to World War I (something something Great War), but the dates didn't work out for that; most of the people involved wd have been fiftyish at the time Woodrow Wilson's war started. And the Spanish-American war seemed unlikely, while the dates were a bit too late for what used to be called the Indian Wars.*
We were without an internet connection in Ferndale, but once we were back in Crescent City I googled the term and discovered its meaning: the person so designated was a member of the Native Sons of the Golden West, a fraternal order for native-born Californians that dates back to 1875, or about a generation after the Gold Rush. Their website (http://www.calnative.org/) talks a bit about their good works and desire to preserve California history.
It was not until I went to The Source of All Knowledge (wikipedia), seeking a second opinion, that their history as the west coast's equivalent to the KKK emerged. Turns out a major part of their purpose was to exclude non-whites from California as much as possible, esp. the Chinese. As late as World War II, they were enthusiastically urging the mistreatment of Japanese Americans. Here's the brief wikipedia entry: http://en.wikipedia.org/wiki/NSGW . Apparently those Bad Old Days of whipping up Yellow Peril hysteria are long past now; good to know.
Or, to adapt one of my favorite sayings: "half a century does not pass in vain".
*or, as my friend Fan Shen called it, "the most successful genocide campaign in modern history".