4. Hurricane Katrina

Credit: AFP/Getty Images
The 2005 storm was a massive disaster, both natural and man-made. Making landfall as a Category 3 storm, Katrina caused an estimated $108 billion in damage, the most ever, and killed as many as 1,800 people. The real tragedy, though, was the seemingly indifferent and less-than adequate response from the federal government, that some still believe is the result of the storm’s victims being predominately low-income minority citizens.
3. Operation Paperclip

Source: Wikipedia
After the Nazis were defeated in WWII, the U.S. government brought 1,500 of their best scientists to the U.S. to work on secret government projects. Many of these scientists had done human experiments on Nazi prisoners, but were pardoned of their war crimes.
2. Jim Crow

Credit: William Lovelace/Hulton Archive/Getty Images
Though the Civil War was won by the North, the fight for racial equality was far from over. Typified by the “separate but equal” laws governing racial interactions, the Jim Crow laws preserved a rigid culture of segregation throughout the South. The various laws of Jim Crow were eventually overturned by Brown v. Board of Education in 1954, the Civil Rights Act of 1964, and the Voting Rights Act of 1965.