United States Navy

====World War II====
{{main|United States Navy in World War II|Naval history of World War II}}
[[File:New Mexico class battleship bombarding Okinawa.jpg|thumb|Battleship {{USS|Idaho|BB-42|6}} [[Battle of Okinawa|shelling Okinawa]] on 1 April 1945]]

The U.S. Navy grew into a formidable force in the years prior to [[World War II]], with battleship production being restarted in 1937, commencing with {{USS|North Carolina|BB-55}}. Though ultimately unsuccessful, Japan tried to neutralize this strategic threat with the surprise [[attack on Pearl Harbor]] on 7 December 1941. Following American entry into the war, the U.S. Navy grew tremendously as the United States was faced with a two-front war on the seas. It achieved notable acclaim in the [[Pacific War|Pacific Theater]], where it was instrumental to the Allies' successful "[[Leapfrogging (strategy)|island hopping]]" campaign.<ref name="Howarth"/> The U.S. Navy participated in many significant battles, including the [[Battle of the Coral Sea]], the [[Battle of Midway]], the [[Solomon Islands Campaign]], the [[Battle of the Philippine Sea]], the [[Battle of Leyte Gulf]], and the [[Battle of Okinawa]]. By 1943, the navy's size was larger than the combined fleets of all the other combatant nations in World War II.<ref name="Tread">{{cite book |last=Crocker III |first=H. W. |title=Don't Tread on Me |publisher=Crown Forum |year=2006 |location=New York |page=[https://archive.org/details/donttreadonme40000croc/page/302 302] |isbn=978-1-4000-5363-6 |url=https://archive.org/details/donttreadonme40000croc/page/302}}</ref> By war's end in 1945, the U.S. Navy had added hundreds of new ships, including 18 aircraft carriers and 8 battleships, and had over 70% of the world's total numbers and total tonnage of naval vessels of 1,000 tons or greater.<ref name="Defense Analysis; Dec 2001, Vol. 17 Issue 3, p. 259–265">{{cite journal |title=Weighing the US Navy |first1=David T. |last1=Burbach |first2=Marc |last2=Devore |first3=Harvey M. |last3=Sapolsky |first4=Stephen |last4=Van Evera |journal=Defense Analysis |volume=17 |issue=3 |date=1 December 2001 |pages=259–265 |doi=10.1080/07430170120093382 |s2cid=153947005}}</ref><ref>{{cite book |last=King |first=Ernest J. |author-link=Ernest J. King |url=http://www.ibiblio.org/hyperwar/USN/USNatWar/USN-King-B.html |title=US Navy at War 1941–1945: Official Report to the Secretary of the Navy |date=3 December 1945 |access-date=8 April 2006 |archive-url=https://web.archive.org/web/20060711124522/http://www.ibiblio.org/hyperwar/USN/USNatWar/USN-King-B.html |archive-date=11 July 2006 |url-status=live}}</ref> At its peak, the U.S. Navy was operating 6,768 ships on [[V-J Day]] in August 1945.<ref>{{cite web |url=http://www.history.navy.mil/research/histories/ship-histories/us-ship-force-levels.html |title=U.S. Navy Active Ship Force Levels, 1886–present |publisher=U.S. Navy |website=[[Naval History & Heritage Command]] |date=20 June 2015 |access-date=20 June 2015 |archive-url=https://web.archive.org/web/20150613070332/http://www.history.navy.mil/research/histories/ship-histories/us-ship-force-levels.html |archive-date=13 June 2015 |url-status=live}}</ref>

[[File:US Navy Issue, 3c, 1945.jpg|thumb|On [[Navy Day#United States|Navy Day]], October 27, 1945, the U.S. Post Office issued a commemorative stamp in honor of the Navy and the end of WW2.]]
Doctrine had significantly shifted by the end of the war. The U.S. Navy had followed in the footsteps of the navies of Great Britain and Germany which favored concentrated groups of battleships as their main offensive naval weapons.<ref>{{cite journal |title=The Evolution of Fleet Tactical Doctrine in the U.S. Navy, 1922–1941 |first=Trent |author1-link=Trent Hone|last=Hone |journal=The Journal of Military History |volume=67 |issue=4 |date=October 2003 |pages=1107–1148 |publisher=Society for Military History |jstor=3396884 |doi=10.1353/jmh.2003.0300|s2cid=159659057}}</ref> The development of the aircraft carrier and its devastating use by the Japanese against the U.S. at Pearl Harbor, however, shifted U.S. thinking. The Pearl Harbor attack destroyed or took out of action a significant number of U.S. Navy battleships. This placed much of the burden of retaliating against the Japanese on the small number of aircraft carriers.<ref>{{cite journal |title=Tactical Use of Air Power in World War II: The Navy Experience |first=Henry M. |last=Dater |journal=Military Affairs |volume=14 |issue=4 |year=1950 |pages=192–200 |publisher=Society for Military History |jstor=1982840 |doi=10.2307/1982840}}</ref> During World War II some 4,000,000 Americans served in the United States Navy.<ref>{{Cite web|url=https://warfarehistorynetwork.com/daily/wwii/expanding-the-size-of-the-u-s-military-in-world-war-ii/|title=Expanding the Size of the U.S. Military in World War II|website=warfarehistorynetwork.com|access-date=13 March 2019|archive-url=https://web.archive.org/web/20180812194913/http://warfarehistorynetwork.com/daily/wwii/expanding-the-size-of-the-u-s-military-in-world-war-ii/|archive-date=12 August 2018|url-status=live|date=26 June 2017}}</ref>