From the book "Tidewater Maryland Architecture and Gardens" by Henry Chandlee Forman:
Page 132 - "The Three Sisters - A Mangling and an Amputation - In 1683 Lord Baltimore granted to Thomas Hilleary I a 1050 acre tract called 'Three Sisters.'On this land, probably soon after the year was erected the small, wooden, gambrel-roofe dwelling stil standing today (p.141).This Thomas Hilleary, it may be noted, married Eleanor sprigg, daughter of Thomas Sprigg I, and half niece of Governor Thomas Stone."
"When Thomas Hilleary died in 1697, he left by will to his wife Eleanor a part of three Sisters, and to his son John Hilleary another part of the same property.His daughters were named as follows:Mary Berry, Elizabeth Lyle, Frances Wilson, Verlinda, and Tabitha."
"Not until some time in the nineteenth century did the house pass rom the Hilleary family, and then to their relatives, the Magruders, who until about 1915 lived at that pleasant seat in Prince George's County."
"At the moment of the writer's visit in 1939, 'The Three Sisters' fireside was suffering from a mangling and amputation which can now be good cause for regret.the huge free-standing chimney seen in the photograph was being demoished brick by brick; and the south part of the dwelling - an addition to the original structure - was in the process of having its walls removed in order to be changed into a porch.Since 1939 much of the domicile has been 'restored' - that is, using the word in quotation marks - but some of the original sash, beaded siding, and molded box cornices remain.The foundation is both brick and stone, and there is a little lie-on-your-stomach window up under the ridge."
"The plan of the abode is simple:on the first storey, two rooms and a passageway and a stair that is steep and plain.all the old mantels have gone, some having been chopped up for firewood.Likewise the many outbuildings have all been lost."
"The Three Sisters is similar in shape and in several other respects to Mount Pleasant, also in Prince George's County, a seat illustrated in Early manor and Plantation Houses of Maryland.The grandson of Thomas Hilleary I, who had the same name, or his great-grandson, Tighlman Hilleary, is reputed to have built Mount Pleasant.It is told that Tilghman Hilleary's son, Washington Hilleary, fought a duel with another man over a lady at the old dueling grounds at Bladensburg, and that every afterward Washington was lame."
"About a quarter of a mile southwest of 'The three Sisters' is the site of another old Hilleary house, destroyed by fire; but there remain two flat slabs marking the graves of Hillearys who were born in the eighteenth century.Still a third Hilleary berth, apparently built before the american Revolution, stands in this area of Prince George's County - but that is another story."