The immigration legislation that set a new limit on migration from other countries, starting at 675,000 each year was the Immigration Act of 1990. This legislation Act also made two other notable changes to the previous immigration Act. The prohibition of immigrants entering US based on their sexual orientation or HIV status was lifted. In addition, the number of visas issued to immigrants was raised from about 54,000 to 140,000.
- this is @shawnlitten 's answer (just to give credit)
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
