The Frederick Swinging Bridge is a small pedestrian suspension bridge originally built to cross Carroll Creek and Bentz Street in the town of Frederick. The bridge was constructed by a local foundry (Buckey and Firestone) at a cost of $685.59. The bridge was moved from its original site in 1928 to the city park. It is the only known surviving iron pedestrian swing bridge in the state.

http://www.sha.state.md.us/keepingcurrent/maintainRoadsBridges/bridges/OPPE/historicBridges/VIII-MSB.pdf