was it also used in any major war?
Yes, World War I.
USS Connecticut (BB-18)
As part of the US response to Germany's unrestricted submarine warfare, "Connecticut" was recommissioned on 3 October 1916. Two days later, Admiral Herbert O. Dunn made her the flagship of the Fifth Battleship Division, transferring his flag from "Minnesota". "Connecticut" operated along the East Coast and in the Caribbean until the United States entered World War I on 6 April 1917. 
what was the uss connecticut bb-18? It the fourth United States Navy ship to be named after the state of Connecticut, was the lead ship of her class of six battleships. when was it built? Her keel was laid on 10 March 1903; launched on 29 September 1904. who designed the ship? UNANSWERABLE where did the ship make her first maiden voyage? She first journeyed south to the Virginia Capes. where is this place located? North America. can you name some regions of the place you just mentioned? Central America and the Caribbean. how is the climate in this place? North America is a very large continent with a varying weather depending on the place. which languages are spoken here? English, Spanish, and French. how can one travel from one place to another here? There is a network of roads. was the ship associated with any flagship? Yes, it served as the flagship for the Jamestown Exposition.
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USS Connecticut (BB-18) [SEP] World War I
As part of the US response to Germany's unrestricted submarine warfare, "Connecticut" was recommissioned on 3 October 1916. Two days later, Admiral Herbert O. Dunn made her the flagship of the Fifth Battleship Division, transferring his flag from "Minnesota". "Connecticut" operated along the East Coast and in the Caribbean until the United States entered World War I on 6 April 1917. For the duration of the war, "Connecticut" was based in York River, Virginia. More than 1,000 trainees—midshipmen and gun crews for merchant ships—took part in exercises on her while she sailed in Chesapeake Bay, and off the Virginia Capes.