Samuel Langley wasn't married and have no children. He spent all his time on scientific projects. One project was a personal dream. He wanted to design and build a flying machine.

Before he left the Allegheny Observatory, he had begun to investigate the possibility. There was little earlier research to guide him. Consequently, he studied the flight of birds and the movement of air over curved surfaces. Langley's interest in the possibility of flight continued when he went to the Smithsonian. He began to build very small airplanes using the rules of flight he had discovered.

On May 6, 1896, Langley's first unmanned plane was launched from the top of a houseboat floating on the Potomac River south of Washington. It flew more than nine-hundred meters and landed softly on the water.

In November of that year, another of Langley's planes made an even longer flight. These were the first free flights of heavier-than-air machines ever made. After the flights, Langley said he had completed the work he wanted to do. He had shown that mechanical flight was possible. Other people, he said, would have to develop the idea further.

Shortly after Langley's successes with his model planes, the United States entered a war with Spain. The American government became interested in developing a fullsize plane that could carry a person. Such a plane could be used to observe the enemy. Balloons had been used to do this for a hundred years. But balloons were difficult to fly.

Therefore, with the support of President William McKinley, the War Department gave Langley fifty-thousand dollars to build a full-size plane. Langley and an engineer, Charles Manley, began designing it. They worked for five years.