What did daniel webster defend in his famous second reply to hayne?
a. great britain and its ban on slavery
b. the south and the institution of slavery
c. the northeast and the sovereignty of the union
d. the west and the displacement of native americans

What did Daniel Webster defend in his famous Second Reply to Hayne?

C. the Northeast and the sovereignty of the Union

Hayne's view - the Union of States was a loose confederation of states/ These states had the right to withdraw from the Union.

Webster's view - any given state could not secede because the Constitution  created a solid union of states/

The answer is option b and c.