May I recommend to you the wonderful two-volume biography of George Whitefield, by Arnold Dallimore and originally published by Banner of Truth (a UK, evangelical publisher). They also publish Whitefield's letters and journal. Both contain the personal correspondence between Franklin and Whitefield.
Franklin was amazed by Whitefield's extraordinary oratory skills and power over his audience and he also found him to be a very nice chap (Which he was. Whitefield had few enemies and was a generous ecumenical peacemaker) Franklin devised a method to help calculate the number of people attending Whitefield's open air meetings (which on more than one occasion numbered over 10,000), and attended these impromptu sermons on numerous occasions. But one thing is clear from Whitefield's journal entries: he regarded Franklin as brilliant but ultimately LOST. He made warm appeals for Franklin's soul, but the elder statesman would have none of that born again "enthusiasm".
Franklin also published Whitefield's sermons and tracts. In fact they became close personal friends. So, to say that Whitefield was without personal influence with the founders, just because Franklin never saw the need for rebirth is ludicrous.
From Ben Franklin's autobiography:
In 1739 arrived among us from Ireland the Reverend Mr. Whitefield,[79] who had made himself remarkable there as an itinerant preacher. He was at first permitted to preach in some of our churches; but the clergy, taking a dislike to him, soon refus’d him their pulpits, and he was oblig’d to preach in the fields. The multitudes of all sects and denominations that attended his sermons were enormous, and it was matter of speculation to me, who was one of the number, to observe the extraordinary influence of his oratory on his hearers, and how much they admir’d and respected him, notwithstanding his common abuse of them, by assuring them they were naturally half beasts and half devils. It was wonderful to see the change soon made in the manners of our inhabitants. From being thoughtless or indifferent about religion, it seem’d as if all the world were growing religious, so that one could not walk thro’ the town in an evening without hearing psalms sung in different families of every street.
And it being found inconvenient to assemble in the open air, subject to its inclemencies, the building of a house to meet in was no sooner propos’d, and persons appointed to receive contributions, but sufficient sums were soon receiv’d to procure the ground and erect the building, which was one hundred feet long and seventy broad, about the size of Westminster Hall;[80] and the work was carried on with such spirit as to be finished in a much shorter time than could have been expected. Both house and ground were vested in trustees, expressly for the use of any preacher of any religious persuasion who might desire to say something to the people at Philadelphia; the design in building not being to accommodate any particular sect, but the inhabitants in general; so that even if the Mufti of Constantinople were to send a missionary to preach Mohammedanism to us, he would find a pulpit at his service.
Mr. Whitefield, in leaving us, went preaching all the way thro’ the colonies to Georgia. The settlement of that province had lately been begun, but, instead of being made with hardy, industrious husbandmen, accustomed to labour, the only people fit for such an enterprise, it was with families of broken shop-keepers and other insolvent debtors, many of indolent and idle habits, taken out of the jails, who, being set down in the woods, unqualified for clearing land, and unable to endure the hardships of a new settlement, perished in numbers, leaving many helpless children unprovided for. The sight of their miserable situation inspir’d the benevolent heart of Mr. Whitefield with the idea of building an Orphan House there, in which they might be supported and educated. Returning northward, he preach’d up this charity, and made large collections, for his eloquence had a wonderful power over the hearts and purses of his hearers, of which I myself was an instance.
I did not disapprove of the design, but, as Georgia was then destitute of materials and workmen, and it was proposed to send them from Philadelphia at a great expense, I thought it would have been better to have built the house here, and brought the children to it. This I advis’d; but he was resolute in his first project, rejected my counsel, and I therefore refus’d to contribute. I happened soon after to attend one of his sermons, in the course of which I perceived he intended to finish with a collection, and I silently resolved he should get nothing from me. I had in my pocket a handful of copper money, three or four silver dollars, and five pistoles in gold. As he proceeded I began to soften, and concluded to give the coppers. Another stroke of his oratory made me asham’d of that, and determin’d me to give the silver; and he finish’d so admirably, that I empty’d my pocket wholly into the collector’s dish, gold and all. At this sermon there was also one of our club, who, being of my sentiments respecting the building in Georgia, and suspecting a collection might be intended, had, by precaution, emptied his pockets before he came from home. Towards the conclusion of the discourse, however, he felt a strong desire to give, and apply’d to a neighbour who stood near him, to borrow some money for the purpose. The application was unfortunately [made] to perhaps the only man in the company who had the firmness not to be affected by the preacher. His answer was, “At any other time, Friend Hopkinson, I would lend to thee freely; but not now, for thee seems to be out of thy right senses.
Some of Mr. Whitefield’s enemies affected to suppose that he would apply these collections to his own private emolument; but I, who was intimately acquainted with him (being employed in printing his Sermons and Journals, etc.), never had the least suspicion of his integrity, but am to this day decidedly of opinion that he was in all his conduct a perfectly honest man; and methinks my testimony in his favour ought to have the more weight, as we had no religious connection. He us’d, indeed, sometimes to pray for my conversion, but never had the satisfaction of believing that his prayers were heard. Ours was a mere civil friendship, sincere on both sides, and lasted to his death.
The following instance will show something of the terms on which we stood. Upon one of his arrivals from England at Boston, he wrote to me that he should come soon to Philadelphia, but knew not where he could lodge when there, as he understood his old friend and host, Mr. Benezet was removed to Germantown. My answer was, “You know my house; if you can make shift with its scanty accommodations, you will be most heartily welcome.” He reply’d, that if I made that kind offer for Christ’s sake, I should not miss of a reward. And I returned, “Don’t let me be mistaken; it was not for Christ’s sake, but for your sake.” One of our common acquaintance jocosely remark’d, that, knowing it to be the custom of the saints, when they received any favour, to shift the burden of the obligation from off their own shoulders, and place it in heaven, I had contriv’d to fix it on earth.
Whitefield's detractors were the Tories of the day.
