Complex sentence: Although, Rivera was intrigued with the industry that revolved around the motor car, he also expressed an interest in the pharmaceutical industry and spent some time at the Parke-Davis Pharmaceutical plant in Detroit to conduct even more research for his commission at the DIA.
Split into simpler sentences: Although, Rivera was obviously intrigued with the industry that revolved around the motor car, he also expressed an interest in the pharmaceutical industry. He even spent some time at the Parke-Davis Pharmaceutical plant in Detroit to conduct even more research for his commission at the DIA.