Length of U.S. participation in major wars

Length of U.S. official participation in major wars

	War	Dates	Duration	Timeline
1.	Vietnam War	1955/11 – 1975/04	19.4 years (19 years, 5 months)
2.	War in Afghanistan	2001/10 – present	11.7 years (11 years, 8 months)
3.	Iraq War	2003/03 – 2011/12	8.7 years (8 years, 9 months)
4.	American Revolutionary War	1775/04 – 1783/09	8.4 years (8 years, 5 months)
5.	American Civil War	1861/04 – 1865/04	4 years
6.	World War II	1941/12 – 1945/08	3.7 years (3 years, 8 months)
7.	Korean War	1950/06 – 1953/07	3.1 years (3 years 1 month)
8.	War of 1812	1812/06 – 1814/12	2.5 years (2 years, 6 months)
9.	Mexican-American War	1846/05 – 1848/02	1.8 years (1 year, 10 months)
10.	World War I	1917/04 – 1918/11	1.6 years (1 year, 7 months)
11.	Spanish-American War	1898/05 – 1898/12	0.7 years (8 months)
12.	Persian Gulf War	1990/08 – 1991/02	0.5 years (6 months)

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(Ongoing wars indicated in bold and with orange bars.) Source: Associated Press

Notes

• Article One, Section Eight of the Constitution gives the United States Congress the power to declare War". Historically wars have been either declared as "Formal" wars or authorized as "Authorized military engagements". In 1973 Congress further clarified their role in authorized armed conflict with the passing of the War Powers Resolution.
• The dates used by the Associated Press for official U.S. involvement in the Vietnam War are August 1964 (the Gulf of Tonkin Resolution) to January 1973 (the Paris Peace Accords), although U.S. military activities and intervention in Vietnam spanned from 1950 to 1975.
• For the Philippine–American War, not included by the Associated Press in their tally above, official start and end dates used by some sources are June 2, 1899 – July 4, 1902, (three years and one month,) although resistance groups continued fighting until June 15, 1913.
• The start date used by the Associated Press for U.S. engagement in the Persian Gulf War is January 17, 1991 (the start of its extensive aerial bombing campaign under the offensive known as Operation Desert Storm.) The first US Combat Troops arrived in South Vietnam in 1965.
• U.S. President Barack Obama pledged in 2009 and 2010 that the U.S. war in Iraq would end by the end of 2011 when all remaining U.S. troops would be withdrawn from Iraq. Then, in the Spring of 2011, Secretary of Defense Gates, went to Iraq, pleading with the government of Iraq, to let U.S. Forces remain past the 2011 deadline.

See also

• American imperialism
• American foreign policy
• CIA sponsored regime change
• Department of Defense
• Declaration of war by the United States
• Military history of the United States
• Military–industrial complex
• Overseas expansion of the United States
• Overseas interventions of the United States
• Relative costs of American wars
• United States and state terrorism
• United States Armed Forces
• United States casualties of war
• War crimes committed by the United States

External links

• Associated Press tally of lengths of U.S. participation in major wars