A little help please

[conkauctions]

New to detecting and went along the old wagon trails at the ridge before the ascent over the mountain. My dad grew up in the area and he says this is the ridge where the wagons would have dumped their stuff if the horses couldn't pull the carriage up hill. Found these under the rock layer and 6-8 inches into the clay. One i believe is a buckle from a saddle or reigns or a stirrup for a child and the other is a leaf spring. My question is what era is the leaf spring from? When did they start using bushings? There is rubber i this spring so i'm thinking maybe civil war time. Any help is appreciated

Thanks