The twelfth amendment to the constitution was added in 1804 in response to the 1800 presidential election. This amendment was meant to break a tie in the presidential election as was witnessed when Thomas Jefferson, a presidential candidate received the same number of electoral votes as Aaron Burr, the vice presidential candidate.
It first started with the Pearl Harbor Attack and was officially announced by Roosevelt in the Quarantine Speech.
It was the name of the boundary that divided Europe at the end of WW2