Looking at it again the source that I was citing is from 2004, which predates Katrina. Looks like it still hasn't bounced back in terms of tonnage passing through the port. But in terms of importance New Orleans isn't diminished; a deepwater port at the mouth of what is by far the country's most significant watershed is always going to be a strategic lynchpin. The entire midwest would be diminished without New Orleans.

Your source is container only.

  Total Tonnage US:

1 Houston, TX 284.9

2 South Louisiana, LA, Port of 238.0

3 New York, NY and NJ 136.6

4 Corpus Christi, TX 111.2

5 Beaumont, TX 101.1

6 New Orleans, LA 92.

7 Long Beach, CA 80.7

8 Baton Rouge, LA 73.4

9 Los Angeles, CA 63.0

10 Virginia, VA, Port of 61.7

11 Lake Charles, LA 58.0

13 Mobile, AL 56.9

14 Plaquemines, LA, Port of 52.8

15 Baltimore, MD 44.2

16 Savannah, GA 41.9

17 Texas City, TX 41.3

18 Huntington - Tristate 36.8

https://www.bts.gov/content/tonnage-top-50-us-water-ports-ra...

These are for containers, New Orleans/BR/S LA is also big in bulk grain, oil and gas, etc, and as for breakbulk see https://www.freightwaves.com/news/port-of-new-orleans-sees-2...