During the war, Girard had to bide his time before resuming his trading on the open seas. His mind, however, was in constant motion with plans and strategies. His maritime trade started to boom. He took a partner, in name only, because he had no intention of delegating anything more than grunt work. His hard work brought him satisfaction. Soon he was recognized for the expert he was. Life was looking up for Stephen Girard.
Since the end of the war, the British were continuing to menace American merchant ships. Not only did they take the cargoes but took possession of the ships as well. It was as if the British had refused to accept their loss of the colonies. After all, they may have concluded, had it not been for the French, the American colonies would still be British. Stephen taught himself to be a privateer and take booty of his own. The US Government approved of private citizens taking on British warships and merchant vessels. Girard had his ships mounted with canon to drive off any pirates, including the British. Despite his requests to President Washington to provide protection for his ships, no official help was forthcoming. It would be several presidential administrations before Girard’s pleas were heeded. Girard’s success continued with trade in the West Indies. With his brother John, he made great strides financially. John was satisfied but Stephen had a more rigorous analysis of his earnings and profit. He was called lucky but his success was not luck but careful analysis of the markets and anticipation for future needs of his clients.
He was reasonably happy at home but there was the beginning of tension with Mary. She seemed to lose her focus on the home she had built with Stephen. In early 1785, the happiness that Girard had realized at home started to unravel. Mary would suddenly shout out incoherently and in uncontrolled anger. These outbursts became more and more frequent. Girard feared the worst. Mental instability and violent rage were signs of impending insanity. Stephen’s brother John who had come to visit his brother and sister-in-law in Philadelphia came to see that his harmless flirting with Mary by letter now seemed to anger her. She could not bear to see John’s two slaves Hannah and her daughter in the house. Even in her confusion she knew that John had fathered the young mulatto girl Rosette. John had hoped to make his stay permanent in a farm near Philadelphia but Stephen discouraged this idea. Stephen reasoned it was bad enough that John planned to leave both slaves with Stephen. Now with Mary’s condition growing worse, he was sorry he had agreed.
During the eight years of his marriage, Mary had not produced a child. Stephen was certain that the fault was Mary’s. After all, the Girards brothers and sisters alike had always been very fertile. Now Girard was faced with an insane wife.
For two years he had her examined by doctors from the hospital. Girard reasoned that life in Philadelphia was perhaps too stressful so he had Mary go off to Mount Holly with her family to find some peace. Her condition grew better for a while and then it grew worse. The doctors recommended that Mary be hospitalized but Girard resisted this recommendation. He had hoped that carriage drives in the country might clear her mind. He even considered that a life in the West Indies might help her. In 1787, Girard had to accept that his wife was incurably insane and had to be hospitalized.
Having spent more than two years without the companionship of a wife, Girard decided to take a mistress.