The Great Depression.
The Reconstruction era began in 1865 and ended in 1877.
Racism continued and blacks still werent treated as equalls, but later on came Martin Luther and that era ended it all.
Slavery ended in the Reconstruction Era, thanks to the 13th Amendment.
Baby Boomers were born after WWII ended. That would be 1947 and after..
the invention of cotton gin by Eil Whitney in 1793
patents and copyrights
World War II.
The railroad system
The Cretaceous- Tertiary Extinction
No... The Holocaust ended before the era called the Cold War began.
Eras are usually either denoted by a start/end event, or the duration over which an event occurs. (For example, the Mesozoic era ended when the dinosaurs went extinct sixty-five million years ago.)
The Battle of Waterloo ended the Napoleonic era.
An asteroid impact
Improvement Era ended in 1970.
When it was formed, it was in the Mesozoic era, but it ended in the Cenozoic era.
1930's era.
Paleozoic era