While growing up in Cedar Rapids, Iowa, Milton Wright, the Wright Brothers' father, liked to purchase toys for his sons that he hoped would stimulate their imagination. One of the most memorable gifts was a toy helicopter that was designed by the French aeronautical experimenter Alphonse Penaud. Milton gave his sons this gift in 1878, and, though it was a simple device with a stick bound to a four-blade rotor set in a spindle, it had the intended effect-it caused them to dream. Twenty-five years separated the gift of this toy and their invention of the airplane, yet the Wright brothers were convinced it had exerted an important influence. Tom Crouch argued in The Bishop's Boys that toys like these perfectly illustrated the significance of play for technological innovation. He wrote, "rotary-wing toys were to intrigue and inspire generations of children, a few of whom would, as adults, attempt to realize the dream of flight for themselves." If the first powered flight on 17 December 1903 represented a childhood dream realized, it was only the first step in the rapid evolution of the airplane from their flimsy kite-like contraption of wood and cloth to jet airliners and rockets in space. And, as extraordinary as the achievement of powered flight seemed in 1903, before the end of the century, space travel also would become a dream realized. Soviet astronaut Yuri Gagarin first circumnavigated Earth in April 1961, and, eight years later, American astronauts took the first steps for humankind on the Moon. It is with great pleasure that we introduce Realizing the Dream: Biographical Essays in Honor of the Centennial of Flight. These essays in celebration of the Wright brothers' first flight 100 years ago grew out of presentations by a group of prominent scholars in 2003 at a conference sponsored by the NASA History Division and held at the Great Lakes Science Center in Cleveland, Ohio. The volume focuses on the careers of some of the many men and women who helped to realize the dream of flight both through the atmosphere and beyond. These accounts are original and compelling because they examine the history of flight through the lens of biography. Collectively, these individuals helped to shape American aerospace history. There are obviously many other individuals that could, and arguably should, have been included in this collection, but we believe that the cross section of diverse individuals contained in this volume is important because it is symbolic of the dream of flight as a whole. These people all devoted their lives, and sometimes even sacrificed them, to the demands required for its realization. The reasons behind the dreams were diverse. The technological potential first demonstrated by the Wright brothers enabled those who followed them to use flight as a means of racial uplift, gender equalization, personal adventure, commercial gain, military superiority, and space exploration. The history of flight is more than a story of technology; it had important cultural consequences as well, and these are some of the themes that the following biographies explore. We have arranged the essays roughly chronologically, though the careers of the people described here often span more than one period of history. None of the people in this volume were inventors like the Wright brothers, but their contributions to flight were nevertheless significant. They were daredevil pilots, entrepreneurs, business men and women, military strategists, and managers of large-scale technology who advanced the art, science, and business of air and space travel, often through sheer force of character. The final paper serves as an epilogue as well as a tribute to the Wright brothers. It describes a reenactment of their important glider experiments at Kitty Hawk, North Carolina, where the Wrights' childhood dream was first realized."