The US Government didnt screw up. Governor Kathleen Blanco screwed up. The federal government can not step into action until the state government declares a state of emergency. She did not do that until about 3 days after Hurricane Katrina came through New Orleans. Once the National Guard was let in General Honere did a great job of aid.
Also, I doubt this is documented anywhere but with all the looting and crime in New Orleans days after the hurricane, some of the National Guard troops were sent to the city [u]without[u] ammo. How do I know this? A friend of mine that I work with went to New Orleans to assist in the rescue efforts. He had to give the National Guard troops from Arkansas ammo.