I can answer the second part the men that controlled them paid very little lots of work hours and no vacations so they made a lot of money while the people made very little
The answer you are looking for is
Democratic Republic of Congo: which gained its independence in 1960
Ghana: which gained its independence 1957
Nigeria: which gained its independence 1960
Hope this helped :D
Answer:
1920s
Explanation:
Nineteenth amendment was adopted