Flagler attended local schools through eighth-grade. His half-brother Daniel had left Hopewell to live and work with his paternal uncle Lamon G. Harkness, who had a store in Republic, Ohio. He recruited Henry Flagler to join him, and the youth went to Ohio at age 14, where he started work in 1844 at a salary of US$5 per month plus room and board. By 1849, Flagler was promoted to the sales staff at a salary of $40 per month. He later joined Daniel in a grain business started with his uncle Lamon in Bellevue, Ohio.