Text below was adapted from The Colonial Homes of Philadelphia and Its Neighborhood,  Adaptation copyright © 2009, The Gombach Group.
Photos: Historic American Buildings Survey. 
Of all the multitudes that each year visit Fairmount Park and pass the door of Belmont Mansion, it is safe to say that hardly one in a thousand thinks of it as the former home of one of the most eminent men of the Colonial and Revolutionary periods. Here was born, here lived, and here died the Honourable Richard Peters, sometime judge of the United States District Court in Pennsylvania, Commissioner of War during the struggle for Independence, and the country's first Secretary of War, in deed, if not in name.
So many changes have been wrought in the house and surroundings since Judge Peters's time, that the picturesque charm of its Colonial character is obscured. It has been turned into a restaurant and so altered and added to that it is not easy to discern what part of the present structure was, in its day, one of the handsomest seats in the neighbourhood. A third floor has been piled atop and wings and back buildings have been built on to such an extent that the original fabric is almost smothered. Examine closely, however, and you will find unmistakable traces of age in parts of the walls. Then enter the distressingly ugly modern doorway and you will find yourself in a delightful room that was once the great hall of the house. The present furnishing of little ice-cream tables and flimsy chairs is sadly out of keeping with the stately panelling and carving and the ornate plaster work of the ceiling — one of the most elaborate examples of Colonial plaster work known — where viols and guitars, trumpets and shepherd's reeds are intermingled with the arms and crest of the Peters family. In the dog-ears of the door-trims are carved dainty little rosettes, while the pediments above are finished with the infinite pains of the woodcarver's art. The embellishment of the overmantel matches the rest of the carved woodwork. If one has the courage to face further desecration to which this lordly old dwelling is subjected, he can pursue his investigations and find other rooms with gems of carving and staircases whose balustrades and spindles might grace a Georgian museum.
... Apart from its commanding site, whence an extensive panorama of the West Park, the Schuylkill River, and part of the city spreads out before the eye, and the beautiful interior woodwork and remarkable ceiling of the great hall, its chief attraction for us lies in the memory of the remarkable man who dwelt under its roof through eighty-four years of an eventful life passed in a most eventful period of our national history.
Belmont, in the township of Blockley, as all that section immediately west of the Schuylkill was called, from Blockley in England whence came the Warner family who first owned this tract, was built in 1742 or 1743 (probably finished in the latter year) by William Peters, the father of the judge. William Peters, who was a younger brother of Richard Peters, sometime secretary of the Land Office, secretary of several Provincial governours, rector of Christ Church and subsequently, by order of the Proprietaries, Councillor of the Province came from England to Pennsylvania prior to 1789 and practiced law in Chester County, which reached at that time to the borders of the city. He seems to have been induced to come out to the Colonies partly to assuage his grief at the death of his first wife, and partly by the fact that his elder brother was already here. In 1741 he married Mary Breintnall, a lady equally charming in character and person, the daughter of a prominent family. It was on the occasion of this marriage that he made his home at Belmont.
Here Richard Peters first saw the light of day in June, 1744. He received his education in Philadelphia, and at the time when he entered upon the practice of law he was known as an excellent Latin and Greek scholar and was well versed in both French and German. His fluency in the latter tongue served him in good stead in his country practice which lay largely among the Germans. Richard Peters was a keen wit and a most brilliant as well as incessant conversationalist. It was his wont to follow the assizes or circuits of the courts in all the surrounding counties, and on these occasions he always relieved the tedium of the legal atmosphere by his humorous sallies. When the Pennsylvania delegation went to the conference with the Indians at Fort Stanwix, in New York State, Peters accompanied them and, during the negotiations, so insinuated himself into the good graces of the Indian chiefs that they proposed to adopt him into their tribe. Their offer was accepted and Peters was introduced to his adoptive relatives by the name "Tegohtias," meaning "Parquet," bestowed in allusion to his amusing talkativeness.
When the storm of the Revolution broke, though his associations with the Proprietary government might have been expected to attach him to the King's interests, he did not hesitate to espouse the defense of American rights and organize a company in the neighborhood of his home, filling the post of captain. His military career, however, was of short duration, for his administrative and executive abilities were so well known that he was soon summoned "from the camp to the cabinet." As Commissioner of War he faithfully and ably served the country in a most difficult and trying position and it is no exaggeration to say that, had it not been for his indomitable energy and unceasing labors, Washington's forces would many a time have been far more sadly handicapped than they were for lack of provisions and ammunition, and it is not impossible that the event of the war might have been different.
Some notion of the Continental Army's frequently grievous state as well as some notion of the tremendous burden Peters bore on his shoulders during all the anxious years of strife may be gained from Peters's own words taken from one of his letters.
I was Commissioner of War in 1779. General Washington wrote to me that all his powder was wet and that he was entirely without lead or balls, so that, should the enemy approach, he must retreat. When I received this letter I was going to a grand gala at the Spanish Ambassador's who lived in Mr. Chew's fine house in south Third street. The spacious gardens were superbly decorated with variegated lamp, the edifice itself was a blaze of lights, the show was splendid, but my feelings were far from being in harmony with all this brilliancy. I met at this party my friend, Robert Morris, who soon discovered the state of my mind. "You are not yourself tonight, Peters, what is the matter?" asked Morris. Notwithstanding my unlimited confidence in that great patriot, it was some time before I could prevail upon myself to disclose the cause of my depression, but at length I ventured to give him a hint of my inability to answer the pressing calls of the Commander-in-Chief. The army is without lead and I know not where to get an ounce to supply it; the General must retreat for want of ammunition. "Well, let him retreat," replied the High and liberal-minded Morris; "but cheer up; there are in the Holker Privateer, just arrived, ninety tons of lead, one-half of which is mine and at your service, the residue you can get by applying to Blair McClenachan and Holker, both of whom are in the house with us." I accepted the offer of Mr. Morris.
Peters then goes on to relate how he approached McClenachan and Holker, both of whom, however, demurred because of the large sums already owing them. Thereupon Morris came forward, assumed the whole responsibility, the lead was delivered and so the army for the nonce had a supply of bullets.
Peters's assiduous labors as Commissioner of War were continued throughout the Revolution, He toiled unceasingly to keep the army furnished with necessary ammunition and supplies at a time "when wants were plenty and supplies lamentably scarce." After the surrender of Cornwallis, Mr. Peters resigned his post in the War Office, December, 1781, whereupon Congress resolved: that Mr. Peter's letter of resignation be entered on the Journal and that he be informed that Congress are sensible of his merit and convinced of his attachment to the cause of his country and return him their thanks for his long and faithful services in the War Department.
Upon leaving the War Office Mr. Peters was elected a member of Congress and had his share in the business of ending the war and arranging the longed-for peace.
Soon after the close of the war, in 1785, Mr. Peters visited England, having among other objects of his visit a commission of a semi-public nature that brought him into acquaintance with the primate and principal prelates of the English Church-the securing of consent for the English bishops to consecrate to the Episcopate three American priests, Doctors White, Moore, and Provoost. His mission, it is needless to say, was ultimately successful. After the conclusion of peace, Mr. Peters was speaker of the State Assembly until President Washington appointed him judge of the United States District Court of Pennsylvania, a position he held until the time of his death thirty-six years later.
During Judge Peters's lifetime, Belmont was the scene of lavish and constant hospitality and while Philadelphia was the seat of Federal government the chief statesmen, diplomats, and foreign notables were frequent guests there. The judge dearly loved to surround himself with his friends, and his political prominence, his intellectual brilliance, and above all his genial personality drew a large coterie about him. Washington and Lafayette were on terms of great intimacy with him and the former, "whenever a morning of leisure permitted," was in the habit of driving to Belmont and there, free for a time from the cares of State, would enjoy his host's vivacious flow of conversation, walking for hours with him in the beautiful gardens between "clipped hedges of pyramids, obelisks and balls" of evergreen and spruce, or beneath the shade of ancient trees. So much for the more serious side of Richard Peters's career.
Notwithstanding his high reputation as a patriot, statesman, and jurist, he is best remembered as a brilliant wit and many stories of his bon mots have been carefully treasured. His was the eminently happy faculty of always being able to raise a wholesome, good-natured laugh without the lead trace of ill-humour or sharpness. Despite his scintillating gaiety, his bursts were always well-timed and his manner and behaviour were never wanting in dignity and decorum. On one occasion the judge was attending a dinner of the Schuylkill Fishing Company and was seated beside the president, Governour Wharton. Toward the end of the dinner more wine was required and the Governour called a serving-man named John to fetch it. Said the judge, "If you want more wine, you should call for the demi-John."
In the latter part of his life Judge Peters was deeply interested in real estate matters and tried to develope a suburban tract he owned. To advertise it he posted a plan of the locality on a signboard and carefully covered it with glass. When asked the reason for the glasscovering, he promptly responded, "Oh, if I leave it exposed, every hunter who comes along will riddle it with shot and then everybody will see through my plan." The project was not successful and one of his friends advised him to have it officially laid out "All right," said Peters, "it's time to lay it out. It's been dead long enough." At another time, according to Samuel Breck, who chronicled a good many of the judge's jeux d'esprit, a very fat and a very slim man stood at the entrance of a door into which his honour wished to pass. He stopped for a moment for them to make way, but perceiving they were not inclined to move, and being urged by the master of the house to come in, he pushed on between them, exclaiming, "Here I go then, through thick and thin."
Judge Peters was one of the founders of the Philadelphia Society for Promoting Agriculture, the first agricultural society in America. From the farm at Belmont came many model things. Dairying among other matters came in for a share of attention and Belmont butter found its way to market put up in one pound packages. Unfortunately for the judge, his one pound weight, according to a new assize of weights and measures, was too light, and the whole consignment was seized by the inspector and confiscated for the benefit of the poor. The judge then sent his old weight to be examined and corrected by the standard, and when it was returned the letters "C.P." (for Commonwealth of Pennsylvania) were stamped upon it. The servant who brought it back carried it at once to the judge, who was at dinner with a party of friends. Taking it he carefully inspected it and looking gravely at his wife, said, as he held it up for her to see, "My dear, they have at last found us out. Here is the old weight come back with C. P. stamped in it which can stand for nothing in the world but Cheating Peters."
Although the surroundings of Belmont were unusually beautiful, so that the French traveller, Chastellux, was quite warranted in his remark about the place being a "tasty little box in the most charming spot Nature could embellish," the fields often presented a shabby appearance, for the judge was so occupied with public affairs and also with agricultural experiments that he had little time to devote to the practical management of his farming operations. One day an old German, who had often read the judge's agricultural reports, made a pilgrimage to Belmont. He found the gate without hinges, fences dilapidated, and the crops not equal to his own. When the judge came out to speak to him, the rustic bluntly expressed his disappointment at the appearance of the place. "How can you expect me," said the judge, "to attend to all these things when my time is so taken up in telling others how to farm?" The old German was disgusted and drove away without asking any more questions.
Judge Peters was one of the courtliest of men and retained the ancient mode of dress long after others had abandoned it. To his dying day he wore knee-breeches and silver buckles on his shoes, always powdered his hair and dressed it in a queue. An old friend of the family, Miss Molly Delaney, was wont to perform the service of queue dressing for him every morning. After his death in 1828 Belmont remained in possession of the family but played no prominent part in the social life of the period. It was sold to the city for incorporation in the park in 1867.