Britain. Thus began the War of 1812 (a bit of a historical curiosity, since the United States declared the war and then waited for Britain to come and fight rather than immediately invading or attacking).
It would be Japan, since after the bombs dropped US forced the Emperor to stepped down.
The ERA is the Equal Rights Amendment, established to guarantee equal rights for women, especially when it came to wage differences between those of the opposite sex. The amendment seemed to fly smoothly until Phyllis Schlafly mobilized conservative women in opposition toward the act. She argued that the act would "disadvantage housewives", but there seemed to be more women for the act, than there were opposing it.
Constantine moved the capital of the Roman Empire because of how dangerous it was to live in.