John Bull was born in Virginia and pursued his early education in Baltimore, Maryland, where he studied medicine. He later settled in Howard County, Missouri, and practiced medicine near Glasgow, Missouri, while also owning slaves. Bull furthered his education by studying theology and was ordained to the ministry, becoming a Methodist minister in Glasgow, Missouri. He spent several years in the public sector, including an unsuccessful run for Missouri governor in 1832 and serving as a presidential elector in 1828. Bull was elected to Congress as an Anti-Jacksonian candidate, serving from 1833 to 1835, after which he returned to his ministerial duties and medical practice.

John Bull's political identity is marked by an intriguing blend of medical, theological, and political pursuits. His ownership of slaves and ministerial work reveals a complex personal history that defies simple categorization. Bull's legislative career as an Anti-Jacksonian candidate suggests a strategic ideological positioning that may not align neatly with traditional party lines. His varied professional background hints at an ideologically agile approach, potentially allowing him to navigate and negotiate across different factions. This multifaceted career trajectory leaves one curious about how Bull reconciles these diverse experiences in his political philosophy.