Samuel claims that he comes from a vault similar to the Vault 76residents, but doesn't state any specific details. He notes that the vault is very far away and extremely well hidden, insisting that the residents wouldn't have heard of it. The dialogue notes indicate that he is lying, supported by the fact that he wears Vault-Tec University athletics gear but doesn't have a Pip-Boy or vault jumpsuit. He often will use words like "yinz," "hoagies" and "jawn," strongly hinting he hails from Pennsylvania.
After the events of Secrets Revealed, the last quest in the Wastelanders main questline, Samuel will become available as a merchant. He sells rare plans to the residents in exchange for gold bullion, with plan rarity dependent on one's reputation with the settlers.
↑Vault 76 resident: "How did you end up here?" Samuel: "I came from a Vault, just like you. You've never heard of it. Its really far away. And hidden. Like really hidden. I don't even know how to get to it. Like at all."