When was a territory eligible for statehood?

A territory was eligible to apply for statehood when the population reached 60,000.

Explanation:

This system remained in place through the admittance of the last two states, Alaska and Hawaii.

the answer is suffrage

on the morning of  july 21,  1861, general mcdowell ordered the  unionarmy to attack. it was on this hill that  confederate  colonel thomas jackson and his forces held back theunion  troops.