What did abraham lincoln declare in his inaugural address?
the north would avenge the attack on fort sumter
no state could lawfully leave the union by its own action
he would abolish slavery
there would be a war

The correct answer is:

No state could lawfully leave the Union by its own action.

Explanation:

Abraham Lincoln was the sixteenth President of the United States of America (1861-1965). Under his inauguration speech on March 4, 1961, Lincoln declared that no state could leave the Union under any condition, he appealed for the conservation of the Union and promised that he wouldn't be the first to attack, but that the government would respond to secession because it would be seen as rebellion. Lincoln also stated that he wouldn't interfere on slavery in states were it was permitted, but slavery became an important issue on the Civil War later on.