The ship was constructed out of white oak and eastern red cedar. The vessel was at the waterline, long at the deck and overall. The ship had a beam of and a depth of hold of , capable of carrying up to 350 barrels of cargo. "Nancy" was 67 tons burthen with two raked masts, square topsails and fore-and-aft mainsails. A figurehead in the shape of a fashionably-dressed lady with a hat and feather was situated on the bow. The ship was armed with two brass cannon mounted on the deck. John Richardson, one of the partners in the company, travelled to the trading post at Detroit to begin construction, accompanied by a master carpenter and six other carpenters. Construction began in late June 1789. On 23 September 1789, Richardson wrote: