There are several black boxes hidden in the campaign mode of Halo Wars for the Xbox 360. The black boxes unlock new Halo History entries. The rest of the black boxes come from winning Skirmishes on each map and winning skirmishes with each leader as well.
Mission 1 Alpha Base – Beneath the last bridge before you enter the rear gates of Alpha Base
Mission 2 Relic Approach – In the area with the supply crates through the Covenant shield with the supply crates, it’s at the top left of the map
Mission 3 Relic Interior – Near the Pelican crash site on the left side of the starting point
Mission 4 Arcadia City – Next to the elevator tower near the controls where you save Adam
Mission 5 Arcadia Outskirts – Off of the road behind the crashed Pelican, down the first ramp
Mission 6 Dome of Light – Where you transported the third Rhino using the Pelican
Mission 7 Scarab – In a cave looking area that contains suppply crates on the right side of the map
Mission 8 Anders’ Signal – On a ridge toward the right where you start on the map
Mission 9 The Flood – On the opposite side of the map from the base, going out from the base ramp
Mission 10 Shield World – Near Bravo platoon right where you picked up the platoon
Mission 11 Cleansing – Requires a flying unit, it’s on the left rear of the ship
Mission 12 Repairs – Near the left side of the Power Core building on the left edge of the Spirit of Fire
Mission 13 Beachhead – Behind the Covenant base on a ledge near the second set of teleporters
Mission 14 Reactor – Go to the first ramp and go up and to the left
Mission 15 Escape – Located between the Covenant base and Flood area in the northern area of the map
