American Queen is a Louisiana-built river steamship said to be the largest river steamboat ever built. Although the American Queen's stern paddlewheel is indeed powered by a steam engine, her secondary propulsion, in case of an emergency and for maneuverability around tight areas where the paddle wheel can not navigate, comes from a set of diesel-electric propellers known as Z-drives on either side of the sternwheel. She has 222 state rooms for a capacity of 436 guests and a crew of 160. She is 418 feet (127 m) long and 89 feet (27 m) wide.

A steamboat is a boat that is propelled primarily by steam power, typically driving propellers or paddlewheels. Steamboats sometimes use the prefix designation SS, S.S. or S/S or PS ; however, these designations are most often used for steamships.