In 1864 it was decreed by Emperor Napoleon III that an international exposition should be held in Paris in 1867. A commission was appointed with Prince Jerome Napoleon as president, under whose direction the preliminary work began. The site chosen for the Exposition Universelle (1867) was the Champ de Mars, the great military parade ground of Paris, which covered an area of 119 acres (48 ha) and to which was added the island of Billancourt, of 52 acres (21 ha). The principal building was rectangular in shape with rounded ends, having a length of 1608 feet (490 m) and a width of 1247 feet (380 m), and in the center was a pavilion surmounted by a dome and surrounded by a garden, 545 feet (166 m) long and 184 feet (56 m) wide, with a gallery built completely around it. In addition to the main building, there were nearly 100 smaller buildings on the grounds.
There were 50,226 exhibitors, of whom 15,055 were from France and her colonies, 6176 from Great Britain and Ireland, 703 from the United States and a small contingent from Canada. The funds for the construction and maintenance of the exposition consisted of grants of $1,165,020 from the French government, a like amount from the city of Paris, and about $2,000,000 from public subscription, making a total of $5,883,400; while the receipts were estimated to have been but $2,822,900, thus leaving a deficit, which, however, was offset by the subscriptions from the government and the city of Paris, so that the final report was made to show a gain.
The exposition was formally opened on April 1, and closed on October 31, 1867, and was visited by 9,238,967 persons, including exhibitors and employees. This exposition was the greatest up to its time of all international expositions, both with respect to its extent and to the scope of its plan.