Shortly after his inauguration, President Jefferson instituted new rules of etiquette and customs of the White House in order to communicate to the public a(n

. political or economical policy that isolates a country from participating in international relationships. it has been suggested that the united states participates in isolationism because of its lack of involvement in particular wars or alliances.

in 1862, president lincoln's emancipation proclamation opened the door for african americans to enlist in the union army. although many had wanted to join the war effort earlier, they were prohibited from enlisting by a federal law dating back to 1792.

explanation:

the correct answwer is d