Winslow House in River Forest, Illinois, designed by Frank Lloyd Wright and built in 1894–95 for ironwork manufacturer William Winslow, marked Wright’s first major independent commission and a turning point he later identified as his first prairie house. The design shows him moving beyond the influence of Louis Sullivan and the James Charnley House toward the Prairie School. Its restrained front emphasizes horizontal bands beneath broad eaves, while the rear is more irregular. Inside, a central fireplace, flanking rooms, and a concealed main staircase anticipate the spatial organization of Wright’s mature work. The house was listed on the National Register of Historic Places in 1970.