What, according to george templeton strong, were major factors that in the autumn of 1860 were about to split the nation

The major causes of secession were Universal suffrage and the abolition.

Explanation:

According to him, the two systems could not work together in the same country because of its hostility. When slaves had territory acquisition then their labor, of free people, would be left out from it.  He thought that the slaves from the South brought ruffianism to the country and the people from the North were corrupts and selfish so that would not help to the good use of universal suffrage.

the correct answer is:

b) a rich merchant.