What was noteworthy about the Seige of Port Hudson in 1863?

The Siege of Port Hudson, Louisiana (May 22 - July 9, 1863), was the final engagement in the Union campaign to recapture the Mississippi River in the American Civil War ... When his assault failed, Banks settled into a 48-day siege, the longest in US military history.

Explanation:

End date: July 9, 1863

Combatants: Union

Part of: American Civil War