As the civil war began president lincoln accepted the belief that

it was time to end slavery throughout the United States.

Explanation:

In 1863, Lincoln's Emancipation Proclamation, which announced that all people held as slaves were free, affected the Union's Civil War efforts by  increasing the number of troops who could join the Union. The reason is the new law permitted African Americans to enlist in the military.

during the 20th century, the role of the vice president has evolved into more of an executive branch position. now, the vice president is usually seen as an integral part of a president's administration and presides over the senate only on ceremonial occasions or when a tie-breaking vote may be needed.