Why did the Union become more concerned with ending slavery during the
Civil War? A. slaves in the northern states began to launch violent protest to demand freedom B. northern leaders hoped to stop southern slaves from escaping to the north C. several border states that allowed slavery seceded from the united states D. union leaders hoped to win more support from the countries that opposed slavery

C. several border states that allowed slavery seceded from the united states.

Explanation:

Before Abraham Lincoln was elected president, in November 1860, seven states seceded from the South and which formed the Confederate States of America.

It wasn't too long, the Civil war began and four more Southern states joined the Confederacy while four border slave states remained in the Union.

Union lost eleven Southern states.

.

they usually pass federal laws

and sometimes in the elections of the president