Here is a great series of three photographs from 1902. It depicts a parade of the Grand Army of the Republic going down Pennsylvania Avenue.
Source: Library of Congress
This was the 36th encampment of the Grand Army in Washington following the end of the Civil War. Below is the program for the festivities that we dug up in The New York Times from August 15th, 1902.
WASHINGTON, Aug. 15. — At a conference to-day at encampment headquarters, presided over by Gen. Eli Torrance, Commander in Chief of the Grand Army of the Republic, the following programme of exercises for the 1902 encampment was adopted:
Sunday, Oct. 5–Patriotic services in various local churches, particularly in New York Avenue Presbyterian Church, where the Rev. Wallace Radcliffe, D. D., will preside, and in St. Patrick’s Catholic Church, where the Rev. D. J. Stafford, D. D., will preside.
Monday, Oct. 6–Campfire in Convention Hall at 7:30 o’clock in the evening, at which the members of the veteran associations will be addressed by speakers of National reputation; S. E. Faunce, Chairman of the local Committee on Campfires, to preside.
Tuesday, Oct. 7–Naval day; parade of special veterans’ associations, detachments of regular troops, district militia, and various civilian organizations to be particularly invited; excursion to Mount Vernon for the delegates of the encampment; public evening meeting of welcome at Convention Hall, at which Chairman Warner of the local Citizens’ Committee will extend the freedom of the city to Gen. Torrance and his associates.
Wednesday, Oct. 8–Grand review of Grand Army of the Republic by the Commander in Chief and the President of the United States with an elaborate reception in the evening at Convention Hall.
Thursday, Oct. 9, and Friday Oct. 10–Sessions of National encampment.