WASHINGTON - America's growing diversity has reached nearly every state. From South Carolina's budding immigrant population to the fast-rising number of Hispanics in Arkansas, minority groups make up an increasing share of the population in every state but one, according to figures released Tuesday by the Census Bureau. "This is just an extraordinary explosion of diversity all across the United States," said William Frey, a demographer at the Brookings Institution, a Washington think tank. "It's diversity and immigration going hand in hand." West Virginia is the exception, with its struggling economy and little history of attracting immigrants. Frey said states...