Centennial of the Launching of the Big Ships U.S. Navy - August 1897 - Philly and Washington Park, Deptford NJ
A possible event connected to the famous 1897 Street Scene Photo (off of a stereograph photo card by "B.W. Kilburn and Company" - Library of Congress) above between 7th and 8th Street on Market Street and the crowds main focus looking east toward 6th Street may be a G.A.R. Grand Army of the Republic, Naval veterans posts event celebrating the launch in Spring 100 years prior, the centennial, of the original 6 ships of the first Official Navy under the U.S. Constitution and the ships built with funds authorized by Congress in 1794. Launched from six shipyards along the east coast in 1797.
The event commemoration on August 12, 1897 was at Independence Hall starting at 12:30 PM.
I would imagine with speeches and music the Navy Vets would have been there at least two hours. And the Vets in parade form then marching over to the Arch Street Wharf, may have used 6th Street - the reason for people in balconies at 7th Street trying to get a glimpse of the then moving event amidst the flags and bunting etc. on Market Street, the main drag through Philly.
A typical muggy Philly August afternoon with a slight overcast of clouds to mute the shadows and direction of shade to indicate a time frame of the day.
That and some folks wanting to take a Ferry over to Washington Park in Deptford Township NJ to get a view of yacht racing and mock naval battles off Fort Mifflin in the late afternoon into evening.
The U.S.S. United States had already been launched in May 1797 from Humphries Shipyard in Philadelphia.
http://military.wikia.com/wiki/Original_six_frigates_of_the_United_States_Navy
Philadelphia Inquirer 13 Aug 1897
https://en.wikipedia.org/wiki/USS_Minneapolis_%28C-13%29
https://en.wikipedia.org/wiki/USS_Katahdin_(1893)
https://en.wikipedia.org/wiki/Amphitrite-class_monitor
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