Mies van der Rohe's love-it-or-hate-it celebration of Modernism endures as a cautionary tale on the merits of glass houses

The Farnsworth House in Plano, Illinois, about 60 miles southwest of Chicago, is revered as one of the world's most important Modernist icons. But architect Ludwig Mies van der Rohe's masterpiece—the glass-walled embodiment of his dictum Less is more—provoked scathing criticism upon its completion in 1951. Edith Farnsworth, the wealthy Chicago physician who had commissioned the house, declared the transparent structure unlivable and filed suit against Mies. She lost the case—she had, after all, approved the plans—and grudgingly spent weekends in her glass box for the better part of two decades.

In 1972 Farnsworth sold the house to Lord Peter Palumbo, a British art collector and a far more appreciative owner, who refurnished it extensively with Mies-designed pieces, invested upwards of $1 million in restoration work, and opened it to the public between 1998 and 2001. Last fall, however, Palumbo announced his intention to auction off the property at Sotheby's. The house had no landmark protection; a prospective buyer was threatening to disassemble the building and move it to a new location. "That was our worst nightmare," says David Bahlman, president of the Landmarks Preservation Council of Illinois, which joined forces with the National Trust for Historic Preservation to swiftly raise more than $7.5 million, topping all bidders at the December sale. The site is now landmarked and will reopen for tours on May 1.

"During Mies's lifetime, this house aroused a great deal of controversy," says Dirk Lohan, grandson of the late architect. "I know he would be pleased that just two generations later, people are fighting to preserve it for posterity." 14520 River Rd., Plano; www.farnsworthhousefriends.org.