Editing History of the United States (section)

=== World War II ===
{{Main|World War II|United States in World War II|Military history of the United States during World War II}}
{{See also|Historiography of World War II|United States home front during World War II}}
[[File:The USS Arizona (BB-39) burning after the Japanese attack on Pearl Harbor - NARA 195617 - Edit.jpg|thumb|The [[USS Arizona|USS ''Arizona'']] burning after the Japanese [[attack on Pearl Harbor]] on December 7, 1941]]
During the Depression, the United States remained focused on domestic concerns. U.S. legislation in the [[Neutrality Acts of the 1930s|Neutrality Acts]] sought to avoid foreign conflicts; however, policy clashed with increasing anti-[[Nazi]] feelings following the German [[invasion of Poland]] in September 1939 that started [[World War II]].<ref name=":13">{{Cite book |last=Black |first=Conrad |title=Roosevelt: Champion of Freedom |url=https://archive.org/details/franklindelanoro00blac |year=2003 |pages=[https://archive.org/details/franklindelanoro00blac/page/648 648]–682 |publisher=Public Affairs |isbn=9781586481841 |author-link=Conrad Black}}</ref> At first, Roosevelt positioned the U.S. as the "[[Arsenal of Democracy]]", pledging full-scale financial and munitions support for the [[Allies of World War II|Allies]] and [[Lend-Lease]] agreements – but no military personnel.<ref name=":13" />

Japan tried to neutralize America's power in the Pacific by [[Attack on Pearl Harbor|attacking Pearl Harbor]] in 1941, but instead it catalyzed American support to enter the war.<ref>{{Cite book |last1=Prange |first1=Gordon W. |title=At Dawn We Slept: The Untold Story of Pearl Harbor |url=https://archive.org/details/atdawnwesleptun00pran |last2=Goldstein |first2=Donald M. |last3=Dillon |first3=Katherine V. |year=1982 |publisher=McGraw-Hill |isbn=9780070506695}}</ref> Roosevelt's [[Executive Order 9066]] resulted in over 120,000 Americans of Japanese descent being [[Internment of Japanese Americans|removed from their homes and placed in internment camps]].<ref>{{Cite web |title=Short History of Amache Japanese Internment Camp |url=https://www.colorado.gov/pacific/sites/default/files/Short%20History%20of%20Amache%20Japanese%20Internment%20Camp_0.pdf |url-status=dead |archive-url=https://web.archive.org/web/20190412042223/https://www.colorado.gov/pacific/sites/default/files/Short%20History%20of%20Amache%20Japanese%20Internment%20Camp_0.pdf |archive-date=April 12, 2019 |access-date=October 9, 2018}}</ref>{{Sfn|Ogawa and Fox|page=135}}<ref name="Richey2007">{{Cite news |last=Richey |first=Warren |date=December 5, 2007 |title=Key Guantánamo cases hit Supreme Court |url=http://www.csmonitor.com/2007/1205/p01s02-usju.html?page=2 |url-status=live |archive-url=https://web.archive.org/web/20180627034530/https://www.csmonitor.com/2007/1205/p01s02-usju.html?page=2 |archive-date=June 27, 2018 |work=[[The Christian Science Monitor]]}}</ref> The Allies fought against Germany in the [[European theater]] and Japan in the [[Pacific War]].<ref name=":24">{{Cite web |title=World War II 1939–1945 |url=https://www.britannica.com/event/World-War-II |access-date=June 7, 2024 |website=Encyclopedia Britannica}}</ref> The United States was one of the "[[Four Policemen|Allied Big Four]]", alongside the [[United Kingdom]], [[Soviet Union]], and [[Republic of China (1912–1949)|China]].<ref>{{cite book |first1=Townsend |last1=Hoopes |author-link1=Townsend Hoopes |first2=Douglas |last2=Brinkley |author-link2=Douglas Brinkley |title=FDR and the Creation of the U.N. |url=https://archive.org/details/fdrcreationofun00hoop |url-access=registration |year=1997 |publisher=Yale University Press |isbn=978-0-300-08553-2 |page=100}}</ref><ref>{{cite book |first=John Lewis |last=Gaddis |author-link=John Lewis Gaddis |title=The United States and the Origins of the Cold War, 1941–1947 |url=https://archive.org/details/unitedstatesorig0000gadd |url-access=registration |year=1972 |publisher=Columbia University Press |isbn=978-0-231-12239-9 |page=25}}</ref>

The U.S. gave the Allied war effort money, food, [[petroleum]], technology, and military personnel. The U.S. focused on maximizing its national economic output, causing a dramatic increase in GDP, the end of unemployment, and a rise in civilian consumption, even as 40% of the GDP went to the war effort.{{Sfn|Kennedy, Freedom from Fear}} A [[Military production during World War II|wartime production boom]] led to the end of the Great Depression. Tens of millions of workers moved into the active labor force and to higher-productivity jobs. Labor shortages encouraged industries to look for new sources of workers, finding new roles for women and Black people. Economic mobilization was managed by the [[War Production Board]].{{Sfn|Kennedy, Freedom from Fear}} Most durable goods became unavailable or were tightly rationed, while housing for industrial jobs was in short supply. Prices and wages were controlled, and Americans saved a high portion of their incomes, which led to post-war growth.<ref>{{Cite book |last=Vatter |first=Harold G. |title=The U.S. Economy in World War II |year=1988 |pages=27–31}}</ref>{{Sfn|Kennedy, Freedom from Fear|pages=615–668}}

The U.S. stopped Japanese expansion in the Pacific in 1942; after the loss of the [[Japanese occupation of the Philippines|Philippines to Japanese]] conquests, as well as a draw in the [[Battle of the Coral Sea]] in May, the American Navy then inflicted a decisive blow at [[Battle of Midway|Midway]] in June 1942. The Allied forces built up a garrison on [[Guadalcanal]] island, formerly held by the Japanese, after the successes of the [[Battle of the Eastern Solomons]] and the [[Battle of Guadalcanal]]. The Japanese then stopped advancing south, and the U.S. began taking [[New Guinea]]. Japan also lost [[Aleutian Islands campaign|their invasion]] of the Alaskan [[Aleutian Islands]], allowing the U.S. to begin attacking the Japanese-controlled [[Kuril Islands]].<ref name=":24" />

American ground forces assisted in the [[North African campaign]] and the [[Fall of the Fascist regime in Italy|collapse of Fascist Italy]] in 1943. A more significant European front was opened on [[D-Day]], June 6, 1944, in which Allied forces invaded [[Nazi-occupied France]].<ref name=":24" /> The Allies began pushing the Germans out of France in the [[Normandy campaign]]. After Allied forces landed at the [[French Riviera]] in [[Operation Dragoon]], Hitler allowed his army to retreat from Normandy.<ref>{{Cite web |title=Normandy Invasion World War II |url=https://www.britannica.com/event/Normandy-Invasion |access-date=June 7, 2024 |website=Encyclopedia Britannica}}</ref> Roosevelt [[Death of Franklin D. Roosevelt|died]] in 1945, and was succeeded by [[Harry Truman]].<ref>{{Cite web |date=2024-05-23 |title=Franklin D. Roosevelt - Accomplishments, New Deal, Great Depression, World War II, & Death |url=https://www.britannica.com/biography/Franklin-D-Roosevelt |access-date=2024-06-12 |website=Britannica.com |language=en}}</ref> The western front stopped short of Berlin, leaving the Soviets to take it in the [[Battle of Berlin]]. The Nazi regime [[German Instrument of Surrender|formally capitulated]] in May 1945, [[End of World War II in Europe|ending the war in Europe]].<ref name=":24" /> 
[[File:Raising the Flag on Iwo Jima, larger - edit1.jpg|thumb|''[[Raising the Flag on Iwo Jima]]'', a photo of [[United States Marine Corps|U.S. Marines]] raising a U.S. flag atop [[Mount Suribachi]] during the [[Battle of Iwo Jima]] on February 23, 1945]]
In the Pacific, the U.S. implemented an [[Leapfrogging (strategy)|island hopping strategy]] toward Tokyo. The Philippines was eventually reconquered, after Japan and the United States fought in history's largest naval battle, the [[Battle of Leyte Gulf]].<ref>{{Cite web |title=The Largest Naval Battles in Military History: A Closer Look at the Largest and Most Influential Naval Battles in World History |url=http://militaryhistory.norwich.edu/largest-naval-sea-battles-in-military-history |url-status=dead |archive-url=https://web.archive.org/web/20150124033426/http://militaryhistory.norwich.edu/largest-naval-sea-battles-in-military-history/ |archive-date=January 24, 2015 |access-date=March 7, 2015 |website=Military History |publisher=Norwich University}}</ref> After the war, the U.S. [[Treaty of Manila (1946)|granted the Philippines independence]].<ref name="Gov.Ph">{{Citation |title=Philippine Republic Day |url=https://www.officialgazette.gov.ph/republic-day/ |archive-url=https://web.archive.org/web/20210729160345/https://www.officialgazette.gov.ph/republic-day/ |archive-date=July 29, 2021 |url-status=dead |publisher=[[Official Gazette (Philippines)]] |access-date=July 5, 2012}}</ref>

Military [[research and development]] increased during the war, leading to the [[Manhattan Project]], a secret effort to harness [[nuclear fission]] to produce [[atomic bombs]];<ref>{{Cite book |last=Rhodes |first=Richard |title=The Making of the Atomic Bomb |year=1995}}</ref> the first nuclear device was [[Trinity (nuclear test)|detonated on July 16, 1945]].<ref>{{Cite web |title=Ralph Smith's eyewitness account of the Trinity trip to watch blast |url=http://www.wsmr.army.mil/PAO/Trinity/Pages/RalphSmithseyewitnessaccountoftheTrinitytriptowatchblast.aspx |url-status=dead |archive-url=https://web.archive.org/web/20140904084107/http://www.wsmr.army.mil/PAO/Trinity/Pages/RalphSmithseyewitnessaccountoftheTrinitytriptowatchblast.aspx |archive-date=September 4, 2014 |access-date=August 24, 2014 |website=White Sands Missile Range, Public Affairs Office}}</ref> U.S. airfields in the [[Mariana Islands]] allowed for easier bombing of Japan and hard-fought U.S. victories at [[Battle of Iwo Jima|Iwo Jima]] and [[Battle of Okinawa|Okinawa]] in 1945.<ref>{{Cite book |last=Spector |first=Ronald H. |title=Eagle Against the Sun |url=https://archive.org/details/eagleagainstsuna0000spec |year=1985 |chapter=12–18 |publisher=Vintage Books |isbn=9780394741017 |author-link=Ronald H. Spector}}</ref> The U.S. prepared to [[Operation Downfall|invade Japan's home islands]], but they [[Atomic bombings of Hiroshima and Nagasaki|dropped atomic bombs]] on the Japanese cities of [[Hiroshima]] and [[Nagasaki]], compelling Japan to surrender and ending World War II.<ref>{{Cite book |last=Giangreco |first=D. M. |title=Hell to Pay: Operation DOWNFALL and the Invasion of Japan, 1945–1947 |year=2009}}</ref> The U.S. [[occupied Japan]] (and [[American occupation zone in Germany|part of Germany]]).<ref>{{Cite book |last=Finn |first=Richard B. |title=Winners in Peace: MacArthur, Yoshida, and Postwar Japan |url=https://archive.org/details/winnerspeacemaca00finn |year=1992 |pages=[https://archive.org/details/winnerspeacemaca00finn/page/n64 43]–103 |publisher=University of California Press |isbn=9780520069091}}</ref> 400,000 American military personnel and civilians were killed.<ref>{{Cite web |last1=Leland |first1=Anne |last2=Oboroceanu |first2=Mari–Jana |date=February 26, 2010 |title=American War and Military Operations Casualties: Lists and Statistics |url=https://fas.org/sgp/crs/natsec/RL32492.pdf |url-status=live |archive-url=https://web.archive.org/web/20181209111557/https://fas.org/sgp/crs/natsec/RL32492.pdf |archive-date=December 9, 2018 |access-date=February 18, 2011 |publisher=Congressional Research Service |page=2}}</ref> Nuclear weapons have not been used since the war ended, and a "[[Long Peace|long peace]]" began between the global powers, but they still competed in the [[Cold War]].{{Sfn|Gaddis, Long Peace}}