From "Port Hudson, Confederate Bastion on the Mississippi" by Hewitt:

"On Feb 22, [1863] Pemberton ordered Rust's brigade to Port Hudson. Some 2800 of the brigade entered the garrison on March 3....The 6th Miss and Rust's 3 batteries followed a few days later."

Rust's Brigade:
35 Ala
9 Ark
1 Confed Bn
12 La
6 Miss
15 Miss
3 batteries