Wright's path: kids' blocks to buildings

In 1876, when Frank Lloyd Wright was 9 years old, his mother brought home Froebel maple blocks from the Philadelphia Centennial Exposition. For the rest of his life, Wright recalled building with the blocks - honing the penchant for geometry that permeated his work. In his 75-year career, Wright designed more than 1,100 structures - including homes, churches, bridges, schools, and New York's Guggenheim Museum.

Born in Wisconsin two years after the Civil War, Wright grew up as the Western frontier was closing. Along with Henry David Thoreau, Ralph Waldo Emerson, and Walt Whitman, he strove to bring man back to nature. His low, horizontal style kept structures near the ground; a propensity to nestle homes in slopes blended them with the landscape.

His quest was to build a purely American architecture, evoking democracy and dignity. Central to this were flowing floor plans - a shock for Americans used to boxy Victorian designs - interiors that open boldly to the outside, and reliance on natural materials.

Wright's work falls roughly into three phases. In his early period, from 1893 to 1909, he invented "prairie houses" - long, low structures with no attics or basements, and bands of windows to emphasize horizontality. "They were inspired by American romanticism, the idea that we take our meaning from the land," says Robert Twombly, author of "Frank Lloyd Wright: His Life and Architecture." "That theme stayed strong throughout his career."

In his second phase, Wright was less productive. He was considered an artist whose time had passed. "People who wanted the hottest thing thought he was passé," says Mr. Twombly. "Fallingwater zoomed him back to the top."

Fallingwater graced the cover of Time in 1938, as well as Architectural Record and Life. It was part of an incredible comeback, along with his Johnson Wax Building and Jacobs I, the first of his inexpensive-yet-functional, single-story "Usonian" homes, of which Kentuck Knob is one. The last decade of Wright's career brought accolades, exhibitions, and seven books, including an architectural treatise.

His 409 extant buildings currently lure more than 1 million visitors annually.