It could mean that even though we had wars in the end a man (the president) continues to help the his people Thrive on and make sure there is peace.
At least that's what i think it means.
The reason i think it means that is because the word "corruption" and "aided by a purist man" corruption shows that America went into war but in the end the "Purist" man helps the American people.
This quote was obviously talking about the Civil War (because Lincoln was currently president at the time) and I believe this dated back during the Gettysburg battle and Lincoln made an address about it.
So it makes sense that's what the quote meant.
Hope this helped :)
Have a great day
