How did runway slaves manage to serve in the army despite the ban on slaves

What was the main argument of plessy in plessy v. ferguson

Mississippi, florida, alabama, georgia, louisiana, and texas all seceded from the union. true or false ?

Which of the following are details about the compromise of 1877? election results in a couple of states were in dispute and too close to call. samuel tilden would be given the win in exchange for the removal of federal troops. the presidential election was close between rutherford hayes and ulysses grant. it was agreed troops would leave the south in exchange for a hayes victory.