He spent much of his time in London, where he now had friends in both the Whig and Tory parties. The leading statesmen thought so highly of his abilities that they frequently asked him to arrange political and personal matters that required tact and diplomatic skill. Sometimes he tried to exercise these qualities by correspondence with the lawmakers of Pennsylvania, and one of his latest efforts was on behalf of the negro slaves in the province. Ten years before he had tried to get justice done to these people, but in vain. Now he felt more strongly than ever that it was wrong to import negroes into the new country as slaves. He worked for this object until he induced the colonial Assembly to try to discourage that traffic by placing a duty on the importing of slaves. In 1711 they prohibited such importation in the future, but no sooner had word of this good law reached England than the government there, in spite of Penn's efforts, canceled the Pennsylvania act. Yet the wisest statesmen in England realized that Penn was right, and that the course he was urging his colony to adopt, not only in regard to negro slavery but in all matters that dealt with human liberty and enlightenment, was the best for the new world to follow. Of Penn's children by his first wife, the lively Letitia married William Aubrey, who was harsh and overbearing to her father and tyrannical toward her. His son William had married, but had become very dissipated during his father's visit to Pennsylvania, and was now the black sheep of the family. He owed a great many debts and was in danger of being put into prison for them, so Penn decided he would be better off in Pennsylvania, and sent him out to Pennsbury. He was to be encouraged to live a healthy outdoor life, and have horses and hounds for hunting foxes, deer, and wolves. The son went out to Pennsbury, and James Logan tried to keep a watchful and restraining eye on him, but he managed to get into almost as much trouble there as he had in London, in spite of all efforts to keep him straight. A great change had come over England since the days when the Stuarts were sovereigns. The old brutal laws had been abolished for the most part, and there was far less cruelty and violence. Instead of the dissolute Charles and the treacherous James, the rulers were honorable and virtuous. There were no longer constant rumors of plots and conspiracies, and all religions were treated fairly. William Penn found that he was no longer needed to help some poor Quaker who had fallen under the disfavor of officers of the law. Now his difficulties were mainly those connected with trying to provide a decent government for his province, and to get enough money from it to pay expenses.