After the events in the capital waste land plans of liberty prime were sent to 5 BoS stations in hopes of re building it. Sadly 4 of the 5 were... how you say blown up by super mutants. The 5th one was located in Kentucky but instead of rebuilding him they decided to turn it into a Mecha. With the plans it made it easier. They just had to modify. What they did was replace the Nukes with a engine, Hollowed the chest a little and placed a small cockpit, they fixed the eye to feed to the cockpit so the driver could see and be protected by the front plate, Last they replaced the hands with machine guns so it has a way to fight. 3 Liberty Mark 321 were released just a year after they started to be built.
Now a war is arising that the BoS has sent its whole army.
To the south a new enemy has arisen Called the red arrow. A Faction of the southern states which has the ability to tame animals. There army is twice the size of the BoS and the Red arrows have been rivals sense a event in texas where the BoS killed a member thinking he was a monster.
Hopefully with this new Weapon the BoS can fight off this foe. Or is it to late for them to win.