Born in Basking Ridge, New Jersey, Brownlee was the President of Merchants’ Bank. After receiving a liberal education, he selected commercial pursuits as his calling in life and went to New York City, where he engaged in the extensive wholesale silk houses kept by Throckmorton & Co. After three years, he decided to seek his fame and fortune in a more favorable field in the west. He first moved to Chicago and remained there for one year before moving to St. Louis in 1839 and becoming a dry good clerk with the firm of Blow & Labaume.He soon won the respect and confidence of his employers and eventually advanced to partner in the establishment. At the death of his partner, he purchased the entire business and it became organized as Brownlee, Homer & Company. He became president of the Millers & Manufacturers’ Insurance Company and the head of the Merchants’ Bank (one of the most respectable moneyed institutions in the state of Missouri at the time.) He was also the first president of the St. Louis Police Board under the system that was inaugurated in order to give Missouri the power over city police because of the division created during the Civil War.