French papermakers Joseph-Michel (1740–1810) and Jacques-Étienne (1745–1799) Montgolfier built the first practical balloon—filled with hot air. On June 5, 1783, the Montgolfiers launched a large balloon at a public gathering in Annonay, France. It ascended for 10 minutes. Three months later, they sent a duck, a sheep, and a rooster up in a balloon—and the animals were landed safely. This success prompted the Montgolfiers to attempt to launch a balloon carrying a human. In October 1783 French scientist Jean-François Pilâtre de Rozier (1756–1785) became the first person to make a balloon ascent, but the balloon was held captive (for safety). The following month he became one of two men to make the first free flight in a hot-air balloon, which ascended to a height of about 300 feet over Paris on November 21, 1783, and drifted over the city for about 25 minutes. Hot-air ballooning, which proved to be better than the rival hydrogen-filled balloon developed in France at about the same time, became very popular in Europe. In January 1785 hot-air balloonists successfully crossed the English Channel, from Dover, England, to Calais, France. Across the Atlantic, hot-air balloons made their debut in the United States in Philadelphia in 1793—before a crowd that included George Washington (1732–1799), who was then president of the United States.