when fremont took command in 1861, with headquarters in st. louis, bush was made his aide-de-camp, with the rank of captain. he submitted to secretary of the treasury chase a plan for a government loan of one hundred million dollars, similar to the famous rothschild premium loans of austria. mr. chase feared its rejection by congress, but was impressed with bush's financial genius, and offered him a treasury clerkship. bush returned shortly afterward to st. louis, and became for six years general freight and passenger agent of the st. louis and iron mountain railroad company.