What were two of Fredrick Douglass's major contributions to the civil war

He encouraged President Lincoln to make the emancipation of slaves the primary aim of the war. He met with the president to discuss equal pay for black soldiers. He made it possible for African Americans to buy plantations in the South.

Explanation:

explanation:

the addition to geographic boundaries that might have  kept the people of the huang river civilization from traveling to far distance region is that they had learned about the other river valley civilizations but feared contact would bring invasion.

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the correct answer is:   the domino theory states that if one country in a region came under the influence of communism, then the surrounding countries would follow in a domino effect.