Why did governments of the south want voters to pledge that they or a family
member were able to vote before 1867

It provided that those who had enjoyed the right to vote prior to 1866 or 1867, and their lineal descendants, would be exempt from recently enacted educational, property, or tax requirements for voting. Because the former slaves had not been granted the franchise until the adoption of the Fifteenth Amendment in 1870, those clauses worked effectively to exclude Black people from the vote but assured the franchise to many impoverished and illiterate whites.

Explanation:

:)

so what is your question?

it was the "4. potsdam" conference that demanded the unconditional surrender of japan, since it was clear that the japanese would continue to find until the very last man otherwise.