I would say the most significant weaknesses of the government under the Articles of Confederation was the fact that the central government was too weak to enforce laws and couldn't impose taxes. The states had the most authority and since the government wasn't able to impose taxes, it doesn't have enough funds for a military (and it had to ask the states for troops). Without a strong military, it will be hard to defend the nation well if anything should occur.
Lincoln Douglas made a point of telling how horrible slavery was in regard to the fact that he was not allowed to have any leisure time, he was often beaten, and was denied access to an education for some time.
Babylon, Perseoplis, and Susa.
Hope this helps!
-Flamepool
<span>Because of The high birth rate</span>