Converted to a "cotton clad" ram by the Confederate Army, thereafter served on the Mississippi and Red Rivers.

On February 24, 1863, under the command of Captain Charles Pierce, she participated in the sinking of the Federal ironclad USS Indianola.

[2][3] On April 23–24, 1865, under the command of Charles S. Read, Webb broke through the Federal blockade at the mouth of the Red River, Louisiana, and made a dramatic run down the Mississippi toward the Gulf of Mexico.

After eluding several United States Navy vessels and passing New Orleans, she was confronted by the powerful steam sloop USS Richmond.

Rather than face the veteran ship's broadside, the Webb was run ashore and destroyed by her crew.