Different reasons for different times for different peoples. No different for any other nation (country). So examples follow:
1. America warred with Britain because it wanted to be its own country (Revolutionary War 1776).
2. The US warred with Britain again because the UK disrespected America by kidnapping US sailors on the high seas.
3. The US warred with the American Indian because the US wanted his land.
4. The US warred with Mexico to because the US wanted his land too; under the slogan of "Manifest Destiny."
5. The US warred with its southern brother in the Civil War because the Rebel wanted to start his own country...and the northern brother wouldn't have it! So they fought about it. And the Northern brother won in 1865.
6. The US warred with Spain because the US wanted Cuban leasing rights, Puerto Rico, the Philippines, etc. and become one of the "big boys on the block" (a fellow colonizer like the Europeans), so when the battlewagon USS Maine exploded in Havanna Harbor 1898...it was war (Spain was blamed for the Maine's sinking...later proved to be an accidental coal explosion).
7. The US warred with Germany in 1917 because Germany stated they were going back to "unrestricted sub warfare" & and the US warned them about that...so war it was.
Just a few examples.
American Revolution
Which American war?
To name a few: American Civil War American Revolutionary War War of 1812 Mexican-American War Spanish-American War World War I World War II Vietnam Gulf War War on Terrorism
Some American wars are the War for Independence, the War of 1812, and the Spanish-American War.
The Philippine American war was the direct response to the Spanish American War.
There is no such conflict as the African American War. You might be thinking of the Mexican-American War.
Spanish American war 1898
The Spanish American War ennded and the Philippine American War began.
The Philippine American War.
In 1607 there was no American War of Independence (that war was 1776).
American Revolution War of 1812 Mexican American War Civil War Spanish American War WWI WWII Korean War Vietnam War Gulf War War on Terrorism
Most people know what the Vietnam War is; what is the American War?