A famous steamer that was in the employee of the federal government. records indicate she was active in the eaters around Helena Ark as early as January 1863. She came to a famous end, burning with 2.6 million dollars of payroll, on August 6 1863 at Cairo IL.
http://www.mohistory.org/files/archives_guides/Steamboats.pdf
"Receipt of the United States to the Regular St. Louis & New Orleans Passenger Packet for transportation of men and supplies on board the steamer Ruth, from Columbus, Kentucky, to Helena, Arkansas, January 24, 1863. Receipt includes engraving of the Ruth. Document contains the stamp of Capt. Charles Parsons, assistant quartermaster at St. Louis."

See contemporaneous article NY Times
http://www.nytimes.com/1863/08/16/news/disaster-mississippi-destruction-steamer-ruth-philadelphia-inquirer.html
http://www.nytimes.com/1863/08/10/news/burning-of-the-steamer-ruth-further-particulars-of-the-disaster.html

and the appropriate hearings:
https://books.google.com/books?id=MaIFAAAAQAAJ&pg=PA91&lpg=PA91&dq=Destruction+of+Steamer+Ruth+by+Fire!&source=bl&ots=G_gx0QQmvg&sig=RlRxMiOcWuW4xUtjXc8XeCV3eGQ&hl=en&sa=X&ved=0CC8Q6AEwA2oVChMI-JaI1cftxgIVSZANCh2sPwVz#v=onepage&q=Destruction%20of%20Steamer%20Ruth%20by%20Fire!&f=false

It appears the thought at the time was the fire was the result of arson staged by rebels. At the time it was on the way to Vicksburg from St. Louis. Eventually Robert Louden was convicted of the deed. He was part of Deacon JW Tucker and Absalom Grimes St.Louis boat-burners.

John R