Birmingham is the largest city in the state of Alabama. With more than 1.1 million people in the metropolitan area, Birmingham is the cultural and economic heart of Alabama. In much of the world, Birmingham is best remembered as the site of racist violence, bombings, and nonviolent protest in the 1960s, when the city was still racially segregated by law. Visitors today are often surprised to find a pleasant green city of ridges and valleys, with many attractive views and friendly, hospitable people. The City of Birmingham is relatively young. Founded in 1871 at the crossing of two railroad lines, it soon became known for its iron and steel industries. Named for England's giant industrial city, Birmingham became a commercial hub as well, and today it is one of the top five banking cities in the United States. "The Magic City" became known as a thriving and quickly growing community in what had once been a "poor, insignificant Southern village." White and black men migrated from rural communities to work in the iron mills, and so did many Greek and Italian immigrants. The Great Depression was disastrous for Birmingham, singled out as the "worst hit" city in America. World War II brought a strong recovery, but air pollution remained a problem. Old-timers recall that it used to take only took a few minutes outdoors for a clean white shirt to turn gray in the sooty Birmingham air. Sloss Furnaces, a preserved iron mill with 1920s blast furnaces, commemorates this side of the city's heritage. The Civil Rights era of the 1960s left lasting impressions of racial conflict, police dogs and fire hoses turned on nonviolent protesters, and the bombing of homes and churches. Martin Luther King Jr.'s "Letter from the Birmingham Jail" became one of the great statements of the nonviolent movement for racial justice in America. The Birmingham Civil Rights Institute and places of reflections such as Kelly Ingram Park symbolize the healing process from within and present a much different picture of a transformed city. Today, Birmingham is a banking and medical center. The University of Alabama at Birmingham and associated hospitals are nationally renowned for their medical programs, research, and services.