[Illustration: WORLD’S COLUMBIAN EXPOSITION, CHICAGO--COURT OF HONOR, LOOKING WEST] A most remarkable result of the aesthetic achievements of the World’s Columbian Exposition was the influence it had on the architecture of several national expositions which were held at the close of the nineteenth and the beginning of the twentieth centuries. The first of these expositions was the Trans-Mississippi Exposition, which was held at Omaha, Nebr., 1897-1898. Several classical buildings were erected for it, as were erected also for the Pan-American Exposition, held at Buffalo, N. Y., in 1901, to emphasize the progress of Americans of the western continents during the nineteenth century. Then followed the Louisiana Purchase Exposition, which ranks as the third great World’s Fair held in this country in 1904, in celebration of the one hundredth anniversary of the transfer of the Louisiana Territory by France to the United States, during the administration of President Jefferson. It is significant that as Thomas Jefferson had introduced the classical style of architecture into this country, so at this Exposition most of the 15 largest buildings resembled in character the classical buildings of the Chicago World’s Fair. The next exposition in which architecture had an important part was the Alaska-Yukon Pacific Exposition, held at Seattle, Wash., in 1909. Again the classical style of architecture was emphasized, and, as at the Chicago Exposition, the buildings had an ivory-white appearance. It was stated at the time: The influences of an Exposition are of course many, but one of the most palpable influences of our American expositions has been their power to stimulate a powerful interest in architecture and building. The beneficent influence of the Chicago World’s Fair on our architecture is of inestimable value, not only for the architects but for the entire country. Many Americans owe their interest in buildings and architecture to a visit to Chicago in 1893, just as many cities and towns recall in their municipal and government structures the revival of classic splendor seen in the stucco palaces of the World’s Fair. The next exposition of importance was the Panama-Pacific Exposition at San Francisco, Calif., held in 1915. In 1906 almost the entire central part of the city had been destroyed by a frightful earthquake and fire. In less than a decade the city was rebuilt, and by 1915 there had also been planned and constructed the great Exposition. Its principal buildings were built in the classical style of architecture. CHAPTER XIII HIGHWAY PLAN OF THE DISTRICT OF COLUMBIA The street-planning process has experienced several stages of development. 1. The narrow streets of Georgetown are typical of the first stage.