The Union won the war for several reasons. First, the Union had a larger population than the Confederacy. This gave the Union a greater pool of soldiers and resources to draw from. Second, the Union had a stronger economy than the Confederacy. This allowed the Union to purchase more weapons and supplies for its soldiers. Third, the Union had better leadership than the Confederacy. President Abraham Lincoln was a skilled leader who was able to unite the North behind the war effort. He was also able to attract talented generals to lead the Union armies.
The war ended in 1865, when the Confederacy surrendered. The Union victory had a profound impact on the United States. It ended slavery and preserved the Union. It also led to the Civil Rights Movement, which fought for the equal rights of African Americans.