Weld planned to attend Harvard as his father had before him; however, during the War of 1812, a British frigate cruising off Boston Harbor captured one of the family's ships carrying a valuable cargo of wine and Spanish silver dollars. This financial disaster ended Weld's plans for Harvard. Instead, Weld became a clerk for an importer in Boston at age 15. By 22 he was in the dry-goods trade, but his partner's lack of business sense put the company in debt.