USS Illinois - Four United States Navy Ships have been named Illinois in honor of the 21st state.

USS Illinois (1864), was a screw sloop-of-war laid down in 1864 but was never completed and broken up for scrap in 1872.

In the 18th century and most of the 19th, a sloop-of-war in the Royal Navy was a warship with a single gun deck that carried up to eighteen guns. The rating system covered all vessels with 20 guns and above; thus, the term sloop-of-war encompassed all the unrated combat vessels, including the very small gun-brigs and cutters. A screw sloop is a propeller-driven sloop-of-war. In the 19th century, during the introduction of the steam engine, ships driven by propellers were differentiated from those driven by paddle wheels by referring to the ship's screws (propellers).

USS Illinois (BB-7), was the lead ship of the Illinois-class of battleships, launched in 1898, renamed Prairie State in 1941 and sold for scrap in 1956

USS Illinois was a pre-dreadnought, Indiana-class battleship built for the United States Navy. She was the lead ship of the Illinois class and was the second ship of the U.S. Navy to be named for the 21st state. Her keel was laid in February 1897 at the Newport News Shipbuilding & Dry Dock Company, and she was launched in October 1898. She was commissioned in September 1901. The ship was armed with a main battery of four 13-inch or 330 mm guns and she had a top speed of 16 knots (18 mph).

Illinois served with the European Squadron from 1902 to 1903, and with the North Atlantic Fleet until 1907, by which time it had been renamed the Atlantic Fleet. During this time, she accidentally collided with two other battleships. From December 1907 to February 1909, she circumnavigated the globe with the Great White Fleet. From November 1912, the ship was used as a training ship. She was lent to the state of New York in 1919 for use as a training vessel for the New York Naval Militia. The ship was converted into a floating armory in 1924 as a result of the Washington Naval Treaty, and it was as a floating armory, barracks and school that she served for the next thirty years. In January 1941 she was reclassified as IX-15 and renamed Prairie State so that her former name could be given to USS Illinois (BB-65), a new Iowa-class battleship. Prairie State was ultimately sold for scrap in 1956.

A replica of the battleship Illinois was a full-scale mockup of this Indiana-class battleship, created as an exhibit for the 1893 World's Columbian Exposition in Chicago.

USS Illinois (BB-65) would have been an Iowa-class battleship, but construction was canceled before launch

The keel of the fifth ship of the Iowa class, Illinois (BB-65), was laid down on January 15, 1945, at Philadelphia Navy Yard. By July 7th the construction had progressed this far and the ship was officially canceled a month later, on August 11, 1945, only about 22% complete. Nothing was done with the ship after that and the remains were finally scrapped in 1958.

USS Illinois was an uncompleted battleship originally intended to be the first ship of the Montana class. However, the urgent need for more warships at the outbreak of World War II and the U.S. Navy's experiences in the Pacific theater led it to conclude that rather than battleships larger and more heavily armed than the Iowa class, it quickly needed more fast battleships of that class to escort the new Essex-class aircraft carriers being built. As a result, hulls BB-65 and BB-66 were reordered and laid down as Iowa-class battleships in 1942. As such, she was intended to be the fifth member of the Iowa-class constructed, and the fourth navy ship to be named in honor of the 21st US state.

Compared to the Montana-class design which would have originally been ordered as BB-65, Illinois would have gained five knots in speed and the ability to transit the locks of the Panama Canal. However, the construction of BB-65 as an Iowa-class battleship also left her with a reduction in her main battery from twelve 16-inch (410 mm) guns to nine, and without the additional armor that she was planned for.

The keel of the fifth ship of the Iowa class, Illinois (BB-65), was laid down on January 15, 1945, at Philadelphia Navy Yard. By July 7th the construction had progressed this far and the ship was officially canceled a month later, on August 11, 1945, only about 22% complete. Nothing was done with the ship after that and the remains were finally scrapped, starting in September of 1958.

USS Illinois (SSN-786), is a Virginia-class submarine, commissioned on October 29, 2016

USS Illinois is a Virginia-class nuclear-powered attack submarine in the United States Navy. Named for the State of Illinois, she is the third vessel to actively serve with the name, the previous two being battleships BB-7 and BB-65. She was built by the Electric Boat division of General Dynamics, the third of their Block III variants which feature a revised bow and technology from the converted sub-class of Ohio guided-missile submarines (SSGN). The contract for the build was awarded on December 22, 2008, to Huntington Ingalls Industries in partnership with Electric Boat, and construction commenced with the keel-laying ceremony on June 2, 2014, at their yard in Groton, Connecticut. 

First Lady Michelle Obama served as the ship's sponsor and christened the boat with a bottle of Champagne on October 10, 2015. Illinois Governor Bruce Rauner was among the officials who spoke at the ceremony on October 10, 2015.

First Lady Michelle Obama christens the boat on October 10, 2015.

The $2.7 billion, 377-foot vessel carries a crew of more than 130 and is capable of missions including anti-submarine warfare, delivery of special forces, and surveillance. Illinois was launched on August 8, 2015, and completed sea trials on August 2, 2016. She was delivered to the Navy on August 27, 2016, and commissioned in a ceremony at Naval Submarine Base New London on October 29, 2016. Michelle Obama, as the sponsor, attended the ceremony and is considered to be an honorary member of the crew due to her support of military families and her involvement with the Illinois crew and their families.

Compiled by Dr. Neil Gale, Ph.D.