Who had the most to gain when african-americans got in trouble for not having a job?

White people.

Explanation:

After civil war, black people had problems to emancipate still. That's why this period is label as 'another form of slavey'. Because african-american from certain job. In that sense, white people were advantage of this situation, because they were able to hire these people.

Another form of gain was the Sharecropping.

it would be  

germany had to pay all damages related to the war.

and i think

germany had to take sole responsibility for the war.