If you think the Krewe of Centaur crowds were huge, you're right on target. Check out the numbers:

The Convention and Tourist Bureau estimates the crowd at 400,000, the largest ever for a local Mardi Gras parade.  Some of the people came from as far away as Ireland and Japan.  Many of the guests were from Texas and Arkansas.  Police did make at least 100 arrests, most involving alcohol: things like public drunkeness or underage drinking.