Samuel P. Langley had been interested in flight, he said, "...as long as I can remember anything." He began aerial experimentation in earnest early in 1887 while employed at the Allegheny Observatory in Pennsylvania, where he had taught physics and astronomy, as well as being director of the observatory. While at Allegheny he built a large whirling table upon which he began a series of "Experiments In Aerodynamics." By mid-January of 1887, Langley was living in Washington, D.C., employed as Assistant Secretary of the Smithsonian Institution, and as of that April he was building rubber band powered model "rubber-pull aerodromes". Langley and his assistants eventually built and tested over 100 of the model "aerodromes" and managed to secure flights of from 6 to 8 seconds and distances of between 80 and 100 feet. On the death of the head of the Smithsonian in November of 1887, Langley assumed the top post of Secretary. In 1889 he tested stuffed birds on the whirling table; a frigate bird, a California condor and an albatross, with the result that none of them would lift as a live bird ought.
In 1891 Langley experimented with steam-engine powered Aerodromes, beginning the series which would lead to the human-carrying machine of 1903. The first of these was designated Aerodrome No. 0 and proved a failure. The second machine, Aerodrome No. 1, was powered by a carbonic acid gas and later by compressed air. Aerodrome No. 2, also built in 1891 was also a disappointment. Aerodrome No. 3 (1892) was of stronger construction and was modified a number of times. A better means of heating the steam was tested on Aerodrome No. 3 and was a decided improvement and was incorporated into Aerodrome No. 4. By the end of 1893 Aerodrome No. 4 was ready for testing and a launching device atop a house boat was built.
Many months were consumed with preparations, but once the tests commenced failure mounted atop failure, through November and December of 1893 and into June of 1894. A seemingly prophetic recurrent difficulty with excessive flexing of the wings resulted in a number of failures and inconsistent results. In October of 1894, Aerodrome No. 4 made a short hop of 130 feet over the Potomac River. Toward the end of 1894 two Aerodromes (the framework of which were built largely of steel) with more adequately wired and braced wings were constructed. Aerodrome No. 5 flew 100 feet during December of 1894. In May of 1895 Langley hired Augustus M. Herring as an assistant. At the end of 1895, Langley was not enthusiastic over the results he had thus far secured, considering the amount of time, effort and money which had been expended.
Considering the difficulties which had been visited on his efforts, it isn't surprising that Langley decided in 1896 to not attempt to build a human-carrying Aerodrome. By May of 1896, however, the circumstances had begun to change. Aerodrome No. 5 had managed two spectacular feats, making circular flights of 3,300 and 2,300 feet, at a maximum altitude of some 80 to 100 feet and at a speed of some 20 to 25 miles an hour. During November of 1896 Aerodrome No. 6 flew 4,200 feet, staying aloft over 1 minute.
By 1897 Langley had, in his mind, concluded his aerial experiments. In June of that year he penned an article for popular and widely-read McClure's Magazine in which he stated "I have thus far had only a purely scientific interest in the results of these labors. Perhaps if it could have been foreseen at the outset how much labor there was to be, how much of life would be given to it, and how much care, I might have hesitated to enter upon it at all. And now reward must be looked for, if reward there be, in the knowledge that I have done the best I could in a difficult task, with results which it may be hoped will be useful to others. I have brought to a close the portion of the work which seemed to be specially mine - the demonstration of the practicability of mechanical flight - and for the next stage, which is the commercial and practical development of the idea, it is probable that the world may look to others. The world, indeed, will be supine if it do (sic) not realize that a new possibility has come to it, and that the great universal highway overhead is now soon to be opened." It's interesting to note that Langley did not encourage those who would follow to develop the techniques and modalities which he had used, he simply encouraged them to pursue "the commercial and practical development of the idea."
Langley continued his work as an astromomer, specializing in solar astromomy, and remained a very active and involved Secretary of the Smithsonian, reinforcing his comments that he had ended his research on flying machines. However, President McKinley prevailed upon Langley to solicit funds from the U.S. Army to construct an Aerodrome capable of carrying a human operator. In December of 1898 Langley agreed, writing a letter to the U.S. Army Board of Ordnance and Fortification in which he stated that he would pursue the matter on his own time and without charge to the Smithsonian or to the U.S. Federal Government. He requested and ultimately received $50,000 from the U.S. Army to cover the costs of the coming two years of construction and experimentation.
The next series of tests proved fruitful. In June of 1899 Aerodrome No. 6 made a circling flight of 1,800 feet, and in July Aerodrome No. 5 flew 2,500 feet. The next machine tested was the Quarter-Size Aerodrome, scaled to one-quarter the size of the planned human-carrying machine. That flying machine made flights of only 150 and 300 feet in June of 1900, but by August of 1903 it had made a flight of 1,000 feet. The next machine to be tested, the Langley Large Aerodrome "A," would carry a human operator.