At the beginning of the 20th century, in 1903, a man Frederick Nicholas Charrington named purchased an island off the coast of Essex with the purpose of turning it into a rehabilitation center. His family had created a successful brewing business, Charrington Brewery
, years ago in the early 18th century. But Frederick had a different calling in life; he disinherited his family's fortune and devoted his life to helping those in need, especially those struggling financially, in abusive relationships, or seeking treatment for addiction. He founded the Causeway Retreat which offered free rehab facilities for alcohol and opioid addiction. The patients would work on the island in exchange for treatment, creating, like Jess says in the show, a bit of a sober oasis.