Why was the history of slavery repressed for so long ?

Slavery lasted in about half of U.S. states until 1865. As an economic system, slavery was largely replaced by sharecropping and convict leasing. By the time of the American Revolution (1775–1783), the status of enslaved people had been institutionalized as a racial caste associated with African ancestry.

1. it was caused by feudalism

2. charlemagne used christianity as a major cornerstone for his rule. cloisters were built all over the empire to act as centers for the (re)population of the vast european wilderness.

3. the europeans feared the next raid every time chetak

i'm not so sure about #6. but i hope i you with the first 3.