Ulysses S Grant headed the union army. Robert Lee headed the southern army.
Step-by-step explanation:
Eleven south states disaffiliated from the union and were headed by Jefferson Davis. Confederacy writhed and wriggled to attain the authentic status under the leadership of Jefferson Davis. He was the only president of the southern confederate states who appealed for peace during civil war in the senate in an expressive manner.
U S Grant was the commander in general who led the northern army during civil war and emerged to be triumphant against the confederacy. Robert Lee headed the southern army. Grant was also famous in the reconstruction of the south after civil war.