He was owner of the Castle Lamp Company (Formerly Atwood-Castle Lamp Company). He began in the umbrella industry and later transitioned into the bicycle industry and the manufacturing of bicycle lamps. He was connected to the Twentieth Century Manufacturing Company with which he traveled extensively in the USA and Europe. He left the bicycle industry to move forward with the automobile industry. He opened a plant of the Castle Lamp Company in Battle Creek Michigan where the company made lamps for motor cars. These lamps were used on some of the Model T's. He later formed the Fred E. Castle Company in Detroit Michigan. It was the sole distributor of the C-H magnetic gear shift used in automobiles such as the Pullman Car. He was associated with the Hayes Wire Wheel company as well as Gray & Davis Lamp Company. He was made a representative of the Flanders automobile company and he opened a showroom in Detroit.
He was a thirty-second degree Mason, his membership being in Adelphic Lodge, No. 348, A. F. & A. M., of New York; Orient Chapter, No. 138, R. A. M., of New York; Clinton Commandery, No. 14, K. T., also in the Empire state; and Michigan Sovereign Consistory, A. A. S. R. He likewise belongs to the Moslem Temple of the Mystic Shrine and the Benevolent Protective Order of Elks, while in club circles he is well known, being a member of the Detroit Athletic, and the Oakland Hills Country Clubs also the Question Club, which is a very select organization, having only seventy-five members in the United States and Canada. He was a member of the Society of Automotive Engineers as well as other automotive industry associations. He was third Vice President of Motor and Accessory Manufacturers.
Some of his business associates were Henry Ford and John Willys.