I believe the answer is "change to meet the needs of a modern society".
<span>The D-day invasion
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The Air War
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<span>The Battle of the Bulge</span>
The freedman's Bureau provided education after the war with federal fundings. The south did not support it.
I'm 99% sure it's D. Not C cause not all were presidents. Not B because only George Washington out of the 4 wrote the Independence. Possibly A. but more likely D