The South based its economy on the use of slaves for agricultural production of things like cotton and tobacco. The North had significant amounts of industry and other finished goods. The South could supply some of the raw materials for the industry of the North. Regardless, the North relied on paid labor.
They pass laws and stuff thats there main job they work for the people
accrued interest is the interest on a bond or loan that has accumulated since the principal investment, or since the previous coupon payment if there has been one already.