Wars Of The United States

Afghanistan—11 years, 5 months (so far)
Vietnam War—10 years, 9 months
Second Iraq War—8 years, 10 months
Revolutionary War—8 years, 5 months
Civil War—4 years, 6 months
World War II—3 years, 9 months
Korean War—3 years, 2 months
War of 1812—2 years, 7 months
Mexican War—2 years, 1 month
First Iraq War—7 months
Spanish-American War—4 months
Robert DeVries
Related articles
Top 10 deadliest American wars (americanlivewire.com)
The Last Time America Declared War (reason.com)