Answer:
The Northwest Ordinance stipulated the creation of at least three but not more than five states out of the Northwest Territory. Once sixty thousand people resided in a territory, they could apply for statehood.
Three of the most common ancient Greek and Roman architectural features that we see today are columns, domes, and arches. On a side note, the Romans were also responsible for the widespread use of concrete because they discovered it was stronger than the commonly used marble and could be shaped instead of needing to be carved.
The Battle of Antietam, also known as the Battle of Sharpsburg. 22,000 casualties, actually.