Because once an indentured servants time is up, you have to let them live their own life, but if you have a slave, you literally own them and keep them until they die if you choose to do so.
Answer:
The League of Five Nations
Explanation:
The chief appointed to lead over the Grand Council of the Iroquois League. The Chief (Tadodaho) of the League always selected from the Onondaga Nation "keepers of the council fire". The Iroquois League is the oldest form of government in America. The league created by five American Indian tribes. These tribes included Oneida, Cayuga, Onondaga, Seneca, and Mohawk called the Five Nations of the League.
Although this is slightly subjective, it would be "William Shakespeare" who is considered the greatest playwright in the English language, due mostly to his incredibly fluid and "natural" style.