The Railroad is one of the major factions players can join and do quests for in Fallout 4. Their sole mission is to free sentient synths from the Institute. Due to this, they are a little different from other factions like the Brotherhood of Steel, Minutemen, and the Institute because their whole organization stands as a reaction to another. They have no pre-war history and rose in response to the actions of the Institute.
The faction started off much later than the others, beginning in the 2220s when Institute scientists first began to create their third generation of synths. These synths were so much like humans, people brought into question whether synths should have rights or not. This was this moral question that the Railroad rose out of, answering it with a resounding, "Yes, synths deserve to be free."
RELATED: Fallout: The History Of The Minutemen
The earliest known leader of the Railroad was a man named Agamemnon. All that is known about him is that he led the faction sometime before 2066, and his headquarters was raided by the Institute. The next leader was a man named Wyatt, and he served the role from 2266 to 2273. According to Desdemona, Wyatt was the one to make the earliest records they have of the Railroad. Wyatt had to basically rebuild the Railroad from the ground up after the Institute raided their old HQ.
Wyatt was not alone though, as the sole survivor of the Institute raid, John D., helped rebuild the organization. Due to how they were attacked, they made the choices for the Railroad's location to always be kept a secret. They also developed the dead drop system and pyramid structure of the organization to make sure information went to the right and most trusted people with no slip-ups. This is how
Read more on gamerant.com