The Confederates are essentially called "rebels" by the fact that they broke away from the union to make their own Sovereign state, namely the Confederate States of America. So during the talks of surrender, Grant made a generous offer. He offered that Lee and his men would NOT be tried for treason under the condition that they turn in their arms. He also allowed them to keep their personal belongings which in a situation such as this, a betrayal of a Union, is almost unheard of. This allowed Lee's men to return home and work on the rebuilding of the South without any fear of repraisal.
The interior of the Anglican Church shows respect for hierarchy with pews reserved for the wealthy members, which stress the importance given to status in the Church.
The Zimmerman Telegram was captured, translated from the English in Room 40. Mexico was told to join the central powers side and in return they will get west, and southwest back from the USA.
Once America gets land, they will not get it back, part of the idea of Manifest Destiny. America can not afford to lose California, and other states.