It seems like nothing is built to last these days.

A steel bridge, however, is not only built to last but joins a proud tradition of steel bridges that have remained steadfastly in service as decades—and, in some cases, centuries—pass, and countless Americans and tons of goods travel over them.

There are thousands of 100-year-old steel bridges spread across the nation. Some are grand. Some are not. Some span mighty rivers. Some span humble country roads. But all have lived through some of the most extraordinary events in modern history.