The steerage is the lowest deck on a ship. It is the space in which second class or third class passengers would be placed during a ship's voyage, usually with limited amenities and very cramped conditions. Passengers looking to travel as inexpensively as possible would travel in the steerage, and in many cases these passengers were not permitted on the upper decks of the ship. Bathroom usage was often limited and food was usually in short supply; what food was supplied was usually of very low quality. Passengers in this level of the ship often had little or no privacy at all.
The name of this level of the deck comes from the term used to guide the ship; steerage is a term used to describe the process of guiding the ship through the water by use of the rudder. The steerage deck was so named because it was on the level of the control apparatuses that connected the rudder to the captain's deck. This level of the ship tended to be quite small as compared to more spacious upper decks, though this level was also most likely to be overcrowded, leading to somewhat hazardous conditions during long voyages.
This level of accommodation was often the most feasible option for immigrants moving to another country. Throughout the 19th and early 20th centuries, many people leaving Europe to make new lives in the United States would endure poor living conditions and spreading diseases on board ships in the steerage deck. Once they arrived in the new country, they would be unloaded and registered, though many were simply sent back to Europe, again in the lowest level of a vessel. While this was a cheap way to travel, it could be an unbearable way to live for the many weeks passengers would spend at sea.
The process of steering the vessel involves using a moving tail piece known as a rudder that will move left or right, depending on the direction in which the ship needs to be steered. The ship needs to be moving forward through the water in order for the rudder to have any effect on directional control; if the vessel is not moving forward, the rudder will have no effect on steering and the vessel will be said to have lost steerage. When the ship is moving forward and the rudder is able to manipulate direction, the boat is said to have steerage way.