The kingdom went into decline from the mid-16th century CE when the Portuguese, put off by the interference of Kongo's regulations on trade, moved their interests further south to the region of Ndongo. The latter kingdom had already defeated a Kongo army in 1556 CE.
It would be a because i had the same question
The problem faced by Weimar Republic are as follows :
1.Due to the heavy war reparations to be paid Germany was economically very weak.
2. France had occupied the Ruhr region of Germany to forcibly pay the war indemnity.
3. Profit from agriculture diminished and there was a large scale unemployment in the country.
4. The Great Depression totally established the economy and the prosperity of some years came to an end.
5. The weimar Republic could not fulfill the ambition of the people. It was a weak government mostly with coalitions ruling at the Centre. The governments were dissolved very frequently.
One effect was selling Native Americans property.