What were the military advantages and disadvantages of the north and south in 1860?

The North had a good manufacturing base, Excellent lines of internal communication (the railroads) and more people.

The South had fewer people and not much manufacturing capability to speak of. The southern economy was primarily agricultural, focused on cotton and tobacco. There were few rail lines available for internal communications. Much of the economy was dependent on shipping their goods to European ports, which made their ship-borne commerce susceptible to blockade and interception.

From every practical point of view, the war was lost before the first shots were fired at Fort Sumter.

The South did have one advantage; one of the finest generals ever to graduate from West Point, Robert E. Lee. It wasn't quite enough.