In the context of the 20th-century history of the United States, the Second Great Migration was the migration of more than 5 million African Americans from the South to the North, Midwest and West. It began in 1940, through World War II, and lasted until 1970. It was much larger and of a different character than the first Great Migration (1916-1930).
In the Second Great Migration, more than 5 million African Americans moved to cities in states in the North, Midwest, and West, including California, where Los Angeles, Oakland, Richmond, and Long Beach offered skilled jobs in the defense industry. Most of these migrants were already urban laborers who came from the cities of the South. In addition, African Americans were still treated with discrimination in parts of the country, and many sought to escape this.
Compared to the more rural migrants of the period 1910-1930, many African Americans in the South were already living in urban areas and had urban job skills before they relocated. They moved to take jobs in the burgeoning industrial cities and especially the jobs in the defense industry during World War II (WWII). Workers who were limited to segregated, low-skilled jobs in some cities were able to get highly skilled, well-paid jobs at California shipyards.
By the end of the Second Great Migration, African Americans had become a highly urbanized population. More than 80 percent lived in cities, a greater proportion than among the rest of American society. Fifty-three percent remained in the Southern United States, while 40 percent lived in the Northeast and North Central states and 7 percent in the West.
While African Americans were often relegated to support roles during World War II, often these roles could be exceedingly hazardous. A munitions explosion at Port Chicago, California, across the bay from San Francisco, claimed the lives of over 200 African Americans in 1944. When some of the workers refused to resume work until conditions were made less hazardous, up to 50 were