It was fitting that the one hundredth anniversary of a great industrial nation should be celebrated by a World's Fair. Such a plan was first publicly proposed for the United States in 1870, by an association of Philadelphia citizens. It was adopted by Congress in the following year, when an act was passed creating a Centennial Commission, to consist of a delegate and an alternate from each State and Territory. The commission organized for the great and difficult work before them by choosing General J. R. Hawley, of Connecticut, president, and by appointing an executive committee, a board of directors, and heads of various administrative bureaus. The Government declined to assume the financial responsibility of the enterprise, but in 1872 Congress appointed a Centennial Board of Finance with power to raise a capital stock of $10,000,000. Shares to the amount of $2,400,000 were soon sold to private citizens. Philadelphia appropriated $1,500,000, and Pennsylvania $1,000,000. In 1876 Congress made a loan to the Board of $1,500,000. Thus the great problem of a financial basis for the enterprise was solved. [Illustration: Pedestrians walking among large buildings.] At the Centennial Exposition, Philadelphia, 1876. The first thought had been to make the exposition exclusively national, but subsequent deliberation made it seem best to widen the plan so that the arts and industries of the entire world should be represented. President Grant formally proclaimed the Exhibition in 1873, and in the following year foreign governments were invited to participate. Thirty-three cordially responded. Meanwhile, the commission was pushing preparations. Philadelphia, the birth-place of the nation, was rightly chosen as the place for this unique memorial of that event. In the beautiful and spacious Fairmount Park, on the high bank of the Schuylkill River, an area of 285 acres was inclosed, and here five main buildings were soon rising rapidly as by magic. Besides these, there were at the time of opening, smaller structures to the number of 175, filling every available space. On May 10th the Exposition was opened with appropriate exercises, in the presence of 100,000 people. Wagner had composed a Centennial March for the occasion. Whittier's Centennial Hymn was sung by a chorus of 1,000 voices. The restored South chanted the praises of the Union in the words of Sidney Lanier, the Georgia poet. President Grant, in a short speech, then declared the International Exhibition open. A procession of dignitaries moved to Machinery Hall, where the President of the United States and Dom Pedro II., Emperor of Brazil, set in motion the great Corliss engine, and with the whirr of spindle and clatter of machinery the world's seventh great fair began. Weeks and months of inspection were necessary to grasp the Exhibition as a whole and in detail, but an imaginary stroll through the grounds will give the reader some general idea of it.