Because they weren't constantly bombed like ther countries which had their infrastructure destroyed. As far as I am aware, not a single bomb fell on mainland United States during World War 2.
Nuclear weapons have only been used in combat on Japan.
Tecumseh was supplied weapons by Britain during his war. This caused major tensions between the countries of America and Britain.
This was the time when weapons and materials were made from bronze because other materials were not available. Population also began to grow during this time period.
Cuba.
The Confederate States of America.
When most of a country's civilians go into industial work during a war. The usually make weapons and other war materials.
Nuclear weapons have only been used in combat on Japan.
weapons
Tecumseh was supplied weapons by Britain during his war. This caused major tensions between the countries of America and Britain.
america
The only country that has ever used nuclear weapons in any war was the US, at the end of WW2.
The United States used the atomic bomb offensively during WWII. That is pretty close to nuclear weapons.
the french
wood
Vietnam.
no one knows
This was the time when weapons and materials were made from bronze because other materials were not available. Population also began to grow during this time period.