I just found (through the Nichi Bei Times) this cool project: the Japantown Atlas.
The Japantown Atlas maps nearly two dozen communities in California where Japanese Americans lived and worked prior to World War II. Drawing from historic maps, business directories, and photos, we show a variety of Japantowns as they existed in 1940.
Our project both memorializes the Issei (first generation Japanese immigrants) in their first 20-50 years in America – the businesses, churches and schools they established – and documents the hometowns that 120,000 Americans of Japanese ancestry were forced to leave behind during their incarceration in “Assembly Centers” and “Internment Camps” during World War II (1942-1946).