The 9-Inch Dahlgrens of the American Swedish Historical Museum
The American Swedish Historical Museum in FDR Park in Philadelphia, Pennsylvania displays two 9-Inch Dahlgren cannons outside of the museum. Since I arrived just after the museum had closed, I had to photograph the cannons from outside the gate, but it was very apparent that both cannons are well preserved. I believe that the cannons are intended to demonstrate the contributions of Rear Admiral John Dahlgren (the son of a Swedish immigrant) and John Ericsson (the Swedish engineer who designed USS Monitor among many other things). Both of the Dahlgrens seem to be mounted on original iron Marsilly broadside carriages.
According to the registry in the appendix to The Big Guns, the two Dahlgrens are:
To the left of the gate: Number 481 manufactured by Cyrus Alger in 1863. It weighs 9,240 pounds, and it is recorded as having served aboard USS Osceola.
To the right of the gate: Number 1133 manufactured by Fort Pitt in 1864. It weighs 9,225 pounds, and it is recorded as having served aboard USS Ticonderoga.