Of the remaining years of Penn's life, we have very imperfect accounts. He edited the works of two Quaker ministers, those of John Whitehead in 1704; those of John Banks, in 1711. In 1709, he wrote "Some account of the Life and Writings of Bulstrode Whitlocke, Esq.," the famous lawyer and stout Puritan, whom he had known and greatly esteemed. He also travelled repeatedly as a minister, and took an active interest in the affairs of the Quakers. Thus, in 1710, Sir D. Dalrymple writes to R. Barclay, junr., who had written to him about the sufferings of Edinbro' Friends:--"I have written fully to Mr. Penn by this post, who had written to me upon the same subject, to whom I refer you." Again, in 1711, he with others waited on the Duke of Ormond (whom he had known before he became a Friend) to thank him for the kindness which he had shewn to Friends in Ireland during his Lord Lieutenancy.
Meantime had occurred the sad troubles with his late agent Philip Ford, which crippled his resources, broke down his health, and even at one time made him a prisoner in the Fleet for debt. Oldmixon states the fact thus:--"The troubles that befel Mr. Penn in the latter part of his life are of a nature too private to have a place in a public history. He trusted an ungrateful, unjust agent too much with the management of it; and when he expected to have been thousands of pounds the better, found himself thousands of pounds in debt: insomuch that he was restrained in his liberty within the privilege of the Fleet by a tedious and unsuccessful law suit, which together with age, broke his spirits, not easy to be broken, and rendered himself incapable of business and society, as he was wont to have been in the days of his health and vigour both of body and mind." The story is a very sad one. Ford was a Quaker lawyer, and undoubtedly Penn had been far too trustful and careless with him. He had even borrowed money from him on the security of his colony. Ford repaid his kindness and trust by cheating him out of thousands, and his widow and son went farther, and tried to snatch the colony from Penn's grasp. But it was ruled that "it would not be decent to make Government ambulatory," and their claim was not allowed.