Born in roughly 1844, Hosea states that he was "raised in the mountains" during his early years. He also mentions that his father lived a life of "sin and debauchery that would make an emperor blush" until he died at age 75, and that he did love him - despite only seeing him 3 times in his life. In his early years, Matthews was briefly a stage actor who had dreams of being a comedian, although he later became an outlaw.

Hosea was once caught stealing a chicken by "some hill country sheriff" who then decided to hang Hosea as a punishment. Fortunately for Matthews, a riot erupted at the hanging when a group of people believed his punishment was unfair. An unknown man came to Hosea's assistance by shooting the rope, thereby freeing him. In the end, the sheriff was hanged and Hosea got away with what he described as "nothing more than a sore neck".

In the mid-1870s, Hosea met another outlaw named Dutch van der Linde at a campfire; he tried to con and rob Dutch, only to realize that Dutch had stolen from him in the meantime. Both saw the skill that the other had and laughed, before deciding to team up together.

The pair found themselves in Kettering, Ohio. They began conning several people, by posing as international merchants and conning twelve locals into investing $300 into a made-up Portuguese shipping company. They were eventually discovered and arrested by Sheriff Carmichael. However, on 9th March 1877, the two managed to escape their cell, robbing and tying up the sheriff in the process. At some point afterwards, the two came across a teenager named Arthur Morgan, who they took under their wing. Hosea describes Arthur as originally being a "delinquent", but he benefitted hugely from the mentoring of his two adoptive fathers, Hosea and Dutch. This group of three would eventually expand over the years and become the Van der Linde gang.

At some stage, Hosea met and fell in love with a woman named Bessie, whom he later married. He later left the gang for a time to be with her, but he slowly drifted back into it over time. Despite this, Bessie understood who Hosea was and the two stayed together, although she died at some point before 1899. Hosea says that he was "drunk for a year" after Bessie's death.

In 1887, the gang committed its first bank robbery, which Hosea was part of. He, Dutch and Arthur raided the bank of Lee and Hoyt and made off with $5000 of gold. After the robbery, they lingered around the town, giving the money away to orphanages and the poor. During its early years, the gang made a genuine attempt to help the poor. However, Hosea eventually became disillusioned with the gang over time, when it stopped helping others and instead focused on its own survival, in addition to becoming increasingly violent. Despite his reservations, Hosea remained a loyal member of the gang.

As of 1899, Hosea is both the most senior member of the gang and Dutch's lieutenant. Intelligent and level-headed, Hosea regularly advises Dutch and is valued for his wisdom. As much as he shares similar ideals, he tends to favour peaceful methods of making money and is more pragmatic in his understanding of what lies in store for the gang.

Hosea'nın geçmişi pek bilinmese de kendisi "dağlarda büyüdüğünü" belirtir. Ayrıca babasını hayatında sadece üç kez görmesine rağmen sevdiğini ve 75 yaşında ölene kadar "günah ve sefahat içinde bir imparatoru bile utandıracak" bir hayat yaşadığından bahseder. Hosea, gençliğinde bir hırsızdı.

Dutch van der Linde ile 1870'lerin ortalarında, birbirlerini soymaya çalıştıklarında tanıştı. Bu olaydan sonra ikili en iyi arkadaş oldular ve birlikte Van der Linde çetesini kurdular. Bir zamanlar, geçici olarak çeteden ayrıldığında Bessie Matthews adında bir kadınla tanıştı ve aşık oldu - ancak Bessie, 1899'dan önce öldü.

Hosea hem çetenin en yaşlı üyesi hem de Dutch'ın en eski dostudur. Zeki ve sağduyulu bir karaktere sahip olan Hosea, düzenli olarak Dutch'a tavsiyelerde bulunur ve çete tarafından bilgeliği konusunda takdir edilir. Dutch ile benzer idealleri paylaşmasına rağmen, çetenin amaçsız katliamlarını desteklemez.