"Fondly do we hope, fervently do we pray, that this mighty scourge of war may speedily pass away.Yet, if God wills that it continue until all the wealth piled by the bondsman's 250 years of unrequited toil shall be sunk, and until every drop of blood drawn with the lash shall be paid by another drawn with the sword, as was said 3,000 years ago, so still it must be said the 'judgments of the Lord are true and righteous altogether.'"

I assume he means that he hopes that the war will be over with soon, but if it has to continue he will still believe that it's Gods will but what I don't understand is the part with the bondsman unrequited soil.