During the civil war, the union navy

The letter C is the right answer.

Explanation:

In 1862, Grant had repeatedly attempted to capture Vicksburg, the last confederate key city that was missing to be captured by the Northerners on the Mississippi River. This attempt began with attacks in the northern sector of the city, which resulted in failure, thanks to the geographical conditions of the region. In April 1863, Grant decided to change his strategy, and on the night of May 18, Grant and some of his forces moved south through the Navy. When the Confederates found out, it was too late, and the Northerners completely surrounded the city, which surrendered on July 4. The Mississippi River was totally in Northern hands.

explanation: d

abraham lincoln  (february 12, 1809  – april 15, 1865) was an american statesman, politician, and lawyer who served as the 16th  president of the united states  from 1861 until  his assassination  in april 1865. lincoln led the nation through the  american civil war, its bloodiest war and its greatest moral, constitutional, and political crisis.[2][3]  he preserved the  union,  abolished slavery, strengthened the  federal government, and modernized  the u.s. economy.